Patent Application
20170265788
The present invention generally relates, in some aspects, to systems and methods for making and using sensors, including nanoprobe sensors, or other devices.
Fluorescent imaging technology has been extensively used to study living cells, including protein function, metastatic processes, and signaling networks. However, reliable fluorophore labeling is laborious and challenging, for example, as proteins are dynamically synthesized and redistribute inside the cells. De novo expression of fluorescent proteins, such as green fluorescent proteins (GFP), can be difficult to implement for non-transfectable cells, and labels can change protein dynamics, especially with proteins where slight modification of the proteins might change the dynamics of the signaling, and further affect the cell response. One example is the tumor suppressor p53, which has been widely regarded as a key target for cancer therapy. Thus, improvements are needed.
The present invention generally relates, in some aspects, to systems and methods for making and using sensors, including nanoprobe sensors, or other devices, such as optical components. The subject matter of the present invention involves, in some cases, interrelated products, alternative solutions to a particular problem, and/or a plurality of different uses of one or more systems and/or articles.
In one aspect, the present invention is generally directed to an article. In one set of embodiments, the article comprises a member comprising a starting portion, an end portion, and a tapered portion connecting the starting portion to the end portion. In some cases, the starting portion has an average cross-sectional diameter of at least about 100 micrometers, the end portion has an average cross-sectional diameter of between about 100 nm and about 2 micrometers and a length of between about 2 micrometers and about 3 mm, and the tapered portion has a length of no more than about 500 micrometers. In addition, in certain embodiments, at least one particle is immobilized relative to the end portion of the member.
According to another set of embodiments, the article comprises a member having a first starting portion, a second starting portion, and a transition portion connecting the first starting portion to the second starting portion. In some cases, the first and second starting portions each have an average cross-sectional diameter of at least about 100 micrometers, and the transition portion has a smallest cross-sectional diameter of between about 50 nm and about 2 micrometers and a length of no more than about 2 mm.
The article, in still another set of embodiments, includes a member comprising a starting portion, an end portion, and a tapered portion connecting the starting portion to the end portion. In some embodiments, the starting portion has an average cross-sectional diameter of at least about 100 micrometers, the end portion has an average cross-sectional diameter of no more than about 100 nm and a length of at least about 2 micrometers, and the tapered portion has a length of no more than about 500 micrometers. In certain cases, the article also comprises a cell, where at least a portion of the end portion of the member is inside the cell.
In yet another set of embodiments, the article comprises a member comprising a starting portion, an end portion, and a tapered portion connecting the starting portion to the end portion. According to some embodiments, the starting portion has an average cross-sectional diameter of at least about 100 micrometers, the end portion has an average cross-sectional diameter of no more than about 100 nm and a length of at least about 2 micrometers, and the tapered portion has a length of no more than about 500 micrometers. In one embodiment, the article also includes an optical component. In some cases, the member is positioned to deliver light to the optical component.
The article, in another set of embodiments, includes a member having a first starting portion, a second starting portion, and an transition portion connecting the first starting portion to the second starting portion. In some embodiments, the first and second starting portions each have an average cross-sectional diameter of at least about 100 micrometers, and the transition portion has a minimum cross-sectional diameter ranging from 50 nanometers to 2 micrometers and a length of no more than about 2 mm. The article may also comprise a substrate comprising an optical component. In some cases, the member is positioned to deliver light to the optical component.
In another aspect, the present invention is generally directed to a method. In one set of embodiments, the method includes an act of determining the vibration amplitude and/or frequency of a member comprising a starting portion, an end portion, and a tapered portion connecting the starting portion to the end portion. In some cases, the starting portion has an average cross-sectional diameter of at least about 100 micrometers, the end portion has an average cross-sectional diameter of between about 100 nm and about 2 micrometers and a length of between about 2 micrometers and about 3 mm, and the tapered portion has a length of no more than about 500 micrometers.
The method, in accordance with another set of embodiments, includes an act of determining the vibration amplitude and/or frequency of a member comprising a member having a first starting portion, a second starting portion, and a transition portion connecting the first starting portion to the second starting portion. In some cases, the first and second starting portions each have an average cross-sectional diameter of at least about 100 micrometers, and the transition portion has a smallest cross-sectional diameter of between about 50 nm and about 2 micrometers and a length of no more than about 2 mm.
In yet another set of embodiments, the method includes acts of partially exposing a member to etchant media comprising an etchant that etches the member, removing the member from the etchant media when a portion of the member has been etched to have an average cross-sectional diameter of no more than about 100 micrometers, and optionally, immobilizing at least one particle onto the etched portion of the member.
Still another set of embodiments are generally directed to a method comprising acts of exposing a member having a first end and a second end to etchant media such that the first end and the second end are not in contact with the etchant media, and removing the member from the etchant media when a portion of the member has been etched to have an average cross-sectional diameter of between about 50 nm and about 2 micrometers.
In one set of embodiments, the method includes acts of partially exposing a member to etchant media that etches the member. In some instances, the etchant media comprises a first phase comprising an etchant, a second phase comprising an oil positioned above the first phase, and a third phase comprising a polar fluid positioned above the second phase.
The method, in another set of embodiments, includes acts of partially exposing a member to etchant media comprising an etchant that etches the member, and altering the concentration of etchant within the etchant media while the member is exposed to the etchant media.
In still another set of embodiments, the method includes acts of partially inserting a member into a cell. In some cases, the member comprises a starting portion, an end portion, and a tapered portion connecting the starting portion to the end portion. In one embodiment, the starting portion has an average cross-sectional diameter of at least about 100 micrometers, the end portion has an average cross-sectional diameter of between about 100 nm and about 2 micrometers and a length of between about 2 micrometers and about 3 mm, and the tapered portion has a length of no more than about 500 micrometers.
The method, in yet another set of embodiments, includes acts of partially inserting a member into a cell, the member comprising a starting portion and a tapered portion, and determining a characteristic of the cell using light propagated through the member. In some embodiments, the starting portion has an average cross-sectional diameter of at least about 100 micrometers, and the tapered portion has a length of no more than about 500 micrometers.
In another aspect, the present invention encompasses methods of making one or more of the embodiments described herein. In still another aspect, the present invention encompasses methods of using one or more of the embodiments described herein.
Other advantages and novel features of the present invention will become apparent from the following detailed description of various non-limiting embodiments of the invention when considered in conjunction with the accompanying figures. In cases where the present specification and a document incorporated by reference include conflicting and/or inconsistent disclosure, the present specification shall control. If two or more documents incorporated by reference include conflicting and/or inconsistent disclosure with respect to each other, then the document having the later effective date shall control.
Non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale. In the figures, each identical or nearly identical component illustrated is typically represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention. In the figures:
The present invention generally relates, in some aspects, to systems and methods for making and using sensors or other devices, such as optical components. One aspect is generally directed to a sensor or other device comprising a nanometer-sized portion. In some embodiments, the sensor can be used to determine various characteristics such as temperature, humidity, an electric field, a magnetic field, an analyte, or the like. For instance, in one embodiment, a portion of a sensor device may be inserted into a cell and used to study the cell, e.g., using optical techniques such as surface plasma resonance. In some embodiments, such sensors or other devices may comprise metal, glass, or other materials, which can be prepared using etching or other techniques.
One aspect of the invention is now described with reference to
Starting portion 12 of member 10 may have any suitable cross-sectional shape, e.g., square or circular, and in some cases, starting portion 12 has substantially the same cross-sectional area within the starting portion. Typically, starting portion 12 has a larger cross-sectional area than tapered portion 14 or end portion 16. In some cases, starting portion may be connected to other portions or components, e.g., as discussed below. As a non-limiting example, in one embodiment, member 10 may be in optical communication with a fiber optic cable, e.g., such that a portion of the member may be determined using an optical sensor via the fiber optical cable.
End portion 16 may also have any suitable cross-sectional shape or area, and the cross-sectional shape may be the same or different from starting portion 12. For example, end portion 16 may be substantially circular in some cases. Typically, end portion 16 has a smaller cross-sectional area than starting portion 12. In some cases, end portion 16 may have a relatively constant cross-sectional area, although it should be understood that end portion 16 may not necessarily be perfectly circular or cylindrical in reality. End portion 16 may also have any suitable length, e.g., a length of at least about 1 micrometers, or other lengths as discussed herein. In addition, it should be understood that in some embodiments, no end portion is present.
Also shown in
In addition, in some cases, more than one starting portion may be present in the member, e.g., with a transition portion between the starting portions. An example may be seen in
As mentioned, such members may form part of a probe, a sensor, or another device, and thus, such members can be used for a variety of purposes. In one set of embodiments, for example, member 10 can be formed from an optical fiber or other light-transmitting material and used to guide or direct light. For instance, light may be applied to starting portion 12, and directed via tapered portion 14 and end portion 16 to a relatively small or focused region, e.g., on a sample (e.g., a biological sample such as a cell) or on an optical component, etc. In some cases, the light may be used to analyze the sample or a portion of the sample, e.g., using techniques such as surface plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS), or other techniques described herein. One or more particles may also be attached or immobilized relative to end portion 16, which can be used to facilitate analysis in certain embodiments.
In addition, in some embodiments, member 10 may be vibrated, and its vibration characteristics such as amplitude and/or frequency can be determined, e.g., optically. The vibration characteristics of the member may be affected by the presence of other portions or components, and this may be used, for example, as a sensor. For instance, one or more reaction entities sensitive to an analyte may be immobilized relative to end portion 16, such that binding or other interaction between an analyte and a reaction entity may alter the vibration of end portion 16. Thus, for example, an antibody can be used for detection of a protein or other antigen, platinum can be used for detection of hydrogen, or a hydrogel can be used for detection of water (e.g., to determine humidity). In some cases, even relatively small amounts of analyte binding may result in determinable changes in certain vibration characteristics. Other non-limiting examples are discussed in more detail below.
In some cases, members such as those shown in
Accordingly, various aspects of the invention are directed to sensors or other devices comprising members having certain shapes and/or dimensions as discussed herein. In some embodiments, the members may be formed from one or materials that are susceptible to etching with a suitable etchant. For instance, the member may comprise materials such as silica or glass, which can be etched using HF (hydrofluoric acid) or BOE (buffered oxide etch). As another example, the member may comprise a metal such as copper, iron, nickel, and/or steel, which can be etched using acids such as HCl (hydrochloric acid), HNO3 (nitric acid), sulfuric acid (H2SO4), and/or other etching compounds such as such as ferric chloride (FeCl3) or copper sulfate (CuSO4). As yet another example, the member may comprise silicon or other semiconductor materials, which can be etched using etchants such as EDP (a solution of ethylene diamine and pyrocatechol), KOH (potassium hydroxide), and/or TMAH (tetramethylammonium hydroxide). The member may also comprise, in some cases, a plastic or a polymer, for example, polymethylmethacrylate, polystyrene, polyperfluorobutenylvinylether, etc., which can be etched using KOH (potassium hydroxide), and/or other acids such as those described herein.
The member may comprise or consist essentially of one material, or more than one material in some embodiments. For instance, in one embodiment, the member is formed from a unitary or a solid piece of material that may be etched as discussed herein. In addition, the member may be relatively stiff, or the member may be flexible or bendable in some cases, depending on the materials forming the member. In some cases, the member may be initially created by pulling a material in a flame or in a laser (e.g., a CO2 laser), e.g., to create an initial taper in the member. For instance, the member, prior to exposure to the etchant media, may have a transition portion connecting the first end to the second end, wherein the transition portion has a maximum cross-sectional diameter of less than about 10 micrometers. However, this is not required, and in other cases, the member is not initially tapered prior to exposure to the etchant media.
The member may also have any suitable shape or size, before and/or after etching. In one set of embodiments, the member may be substantially cylindrical or rod-shaped. The member may have any suitable cross-sectional shape, for example, square, circular, triangular, ellipsoidal, polygonal, a star, an irregular shape, etc. The member may maintain the same cross-sectional shape throughout its length, or there may be different cross-sectional shapes in different portions of the member.
The member may also have any suitable dimension. In some cases, the member may have an average cross-sectional diameter of at least about 1 micrometer, at least about 2 micrometers, at least about 3 micrometers, at least about 5 micrometers, at least about 10 micrometers, at least about 20 micrometers, at least about 30 micrometers, at least about 50 micrometers, at least about 75 micrometers, at least about 100 micrometers, at least about 200 micrometers, at least about 300 micrometers, at least about 500 micrometers, at least about 750 micrometers, at least about 1 mm, at least about 2 mm, at least about 3 mm, at least about 5 mm, at least about 7.5 mm, at least about 10 mm, at least about 20 mm, at least about 30 mm, at least about 50 mm, at least about 75 mm, at least about 100 mm, etc. The cross-sectional dimension of a non-circular cross-sectional shape may be taken as the diameter of a perfect circle having the same area as the cross-sectional shape. In addition, the member can have a cross-sectional area that is substantially the same along the length of the member. However, in some cases, the cross-sectional area may not be substantially the same along the length of the member, although the average cross-sectional area can be determined by mathematically averaging the average cross-sectional areas throughout the member.
The member may also have any suitable length. For instance, the length of the member may be at least about at least about 1 mm, at least about 3 mm, at least about 5 mm, at least about 10 mm, at least about 30 mm, at least about 50 mm, at least about 100 mm, at least about 300 mm, at least about 500 mm, at least about 1 m, at least about 3 m, at least about 5 m, etc.
As noted above, in some cases, the member may comprise various portions, e.g., as determined by etching, or other techniques. For instance, in one set of embodiments, a member may comprise a starting portion, an end portion, and a tapered portion. In another set of embodiments, a member may comprise a transition portion as discussed herein. In one set of embodiments, a member can be formed by partially exposing the member to an etchant, where the starting portion is not substantially exposed to the etchant, while the end portion is exposed to the etchant (e.g., submerged) and the tapered portion is partially exposed to the etchant, e.g., via a meniscus. It is to be noted that in some cases, however, the transitions between these regions are not sharp or mathematically precise.
The starting portion, which may be the unetched portion of the member, may have any of the shapes, dimensions, or average cross-sectional diameters discussed above for the member. In addition, in some embodiments, the starting portion may be relatively large, compared to other portions of the member. In some cases, the starting portion may have a length of at least about at least about 1 mm, at least about 3 mm, at least about 5 mm, at least about 10 mm, at least about 30 mm, at least about 50 mm, at least about 100 mm, at least about 300 mm, at least about 500 mm, at least about 1 m, etc.
Other portions of the member, in contrast, may be smaller than the starting portion, at least in cross-sectional area or dimension. For instance, in some cases, an end portion or a transition portion of the member may have an average cross-sectional dimension that is less than about 50%, less than about 40%, less than about 30%, less than about 25%, less than about 20%, less than about 15%, less than about 10%, or less than about 5% of the average cross-sectional dimension of the starting portion.
In some cases, an end portion or a transition portion may have an average cross-sectional diameter of no more than about 50 micrometers, no more than about 40 micrometers, no more than about 30 micrometers, no more than about 25 micrometers, no more than about 20 micrometers, no more than about 15 micrometers, no more than about 10 micrometers, no more than about 5 micrometers, no more than about 3 micrometers, no more than about 2 micrometers, no more than about 1 micrometer, no more than about 750 nm, no more than about 500 nm, no more than about 250 nm, no more than about 100 nm, no more than about 75 nm, no more than about 50 nm, etc. In some cases, an end portion or a transition portion may have an average cross-sectional diameter that is at least about 50 nm, at least about 75 nm, at least about 100 nm, at least about 250 nm, at least about 500 nm, at least about 750 nm, at least about 1 micrometer, at least about 3 micrometers, at least about 5 micrometers, at least about 10 micrometers, at least about 15 micrometers, at least about 20 micrometers, at least about 25 micrometers, at least about 30 micrometers, at least about 40 micrometers, at least about 50 micrometers, etc. In addition, combinations of any of these are also possible; for example, the average cross-sectional diameter may be between about 100 nm and about 2 micrometers.
An end portion or a transition portion may also have any suitable shape or cross-sectional area. In some cases, the end portion or the transition portion is substantially cylindrical or rod-shaped, or the end portion may have a circular cross-sectional shape. The end portion or the transition portion may be straight, or bent or curved in some cases. The end portion or the transition portion may have the same cross-sectional dimension throughout its length, or there may be slight variations in cross-sectional shape or dimension, e.g., due to imperfections in the formation process, or due to intentional variations. In some cases, a minimal cross-sectional area or dimension of an end portion or a transition portion may be greater than about 80%, greater than about 85%, greater than about 90%, greater than about 95%, or greater than 97% of the average cross-sectional area or dimension of the end portion or the transition portion.
Certain embodiments of the present invention are generally directed to end portions or transition portions that are relatively long. For instance, an end portion or a transition portion may have a length of at least about 50 nm, at least about at least 100 nm, at least about 200 nm, at least about 300 nm, at least about 500 nm, at least about 1 micrometer, at least about 2 micrometers, at least about 3 micrometers, at least about 5 micrometers, at least about 10 micrometers, at least about 20 micrometers, at least about 30 micrometers, at least about 50 micrometers, at least about 75 micrometers, at least about 100 micrometers, at least about 200 micrometers, at least about 300 micrometers, at least about 500 micrometers, at least about 750 micrometers, at least about 1 mm, at least about 2 mm, at least about 3 mm, at least about 5 mm, at least about 7.5 mm, at least about 10 mm, etc. In some cases, however, an end portion or a transition portion may have a length of no more than about 10 mm, no more than about 7.5 mm, no more than about 5 mm, no more than about 3 mm, no more than about 2 mm, no more than about 1 mm, no more than about 750 micrometers, no more than about 500 micrometers, no more than about 300 micrometers, no more than about 200 micrometers, no more than about 100 micrometers, no more than about 75 micrometers, no more than about 50 micrometers, no more than about 30 micrometers, no more than about 20 micrometers, no more than about 10 micrometers, no more than about 5 micrometers, no more than about 3 micrometers, no more than about 2 micrometers, no more than about 1 micrometer, no more than about 500 nm, no more than about 300 nm, no more than about 200 nm, no more than about 100 nm, no more than about 50 nm, etc. Combinations of any of these are possible, e.g., a length of between about 2 micrometers and about 3 mm. Surprisingly, relatively long end or transition portions, often having substantially constant and narrow diameters, are difficult to fabricate using conventional technologies.
Between the end portion and the starting portion may be a tapered portion or a transition region. The taper between the end portion and the starting portion may be relatively smooth in some cases, and may present a linear profile, or a non-linear or curved profile in some cases, e.g., as is shown in
The tapered portion may be relatively short in some cases. However, relatively short taper regions have not been successfully achieved in the past; for example drawing technologies, where a rod of material is heated and pulled apart to form a tapered portion leading to a smaller diameter, generally results in tapering lengths measured on the order of meters.
However, certain embodiments of the invention are directed to lengths of the tapered portion of less than about 1 m, less than about 300 mm, less than about 100 mm, less than about 30 mm, less than about 10 mm, less than about 3 mm, less than about 1 mm, less than about 500 micrometers, less than about 300 micrometers, less than about 100 micrometers, less than about 50 micrometers, less than about 30 micrometers, less than about 10 micrometers, less than about 5 micrometers, less than about 3 micrometers, or less than about 1 micrometer. In addition, in some cases, the tapered region may be at least about 1 micrometer, at least about 3 micrometers, at least about 5 micrometers, at least about 10 micrometers, at least about 30 micrometers, at least about 50 micrometers, at least about 100 micrometers, at least about 300 micrometers, at least about 500 micrometers, at least about 1 mm, at least about 3 mm, at least about 5 mm, at least about 10 mm, at least about 30 mm, at least about 100 mm, etc. Combinations of any of these are also possible; for instance, the tapered region may have a length of between about 100 micrometers and about 500 micrometers.
The end portion or the transition portion may have any suitable cross-sectional shape, for example, square, circular, triangular, ellipsoidal, polygonal, a star, an irregular shape, etc. The end portion or the transition portion may have a profile that is linear, or non-linear or curved profile in some cases. In some cases, the profile may be irregular. Examples of end portions with various profiles can be seen in
In addition, in some embodiments, as is shown in
As mentioned, in some cases, one, two, or more particles may be fastened or immobilized to the member, e.g., to an end portion, transition portion, or other portions as discussed herein. The particles may be fastened or immobilized on any suitable location, e.g., on a side or end of the end portion. The particle may be fastened or immobilized to the member using adhesives, or other techniques such as those discussed herein. The particles may be of any shape or size, and if more than one particle is present, the particles may be of substantially the same shape and/or size, and/or different shapes and/or sizes. The particles may be substantially spherical, or non-spherical in some cases. For example, the particles may include nanorods or elongated structures, having any suitable aspect ratio (largest dimension to smallest dimension, e.g., about 1:1, about 2:1, about 3:1, about 5:1, about 10:1, etc. The particles may be formed from any suitable material. In one set of embodiments, the particles comprise a metal (gold, silver, copper, etc.), a polymer (e.g., polyethylene), silica or glass, etc. In one embodiment, the particle is a nano-diamond. Many such particles may be readily obtained commercially.
Those of ordinary skill in the art will be able to determine the average cross-sectional diameter of a single particle and/or a plurality of particles, for example, using laser light scattering, microscopic examination, or other known techniques. The average cross-sectional diameter of a single particle, in a non-spherical particle, is the diameter of a perfect sphere having the same volume as the non-spherical particle. The average cross-sectional diameter of a particle (and/or of a plurality or series of particles) may be, for example, less than about 1 mm, less than about 300 micrometers, less than about 100 micrometers, less than about 30 micrometers, less than about 10 micrometers, less than about 3 micrometers, less than about 1 micrometer, less than about 800 nm, less than about 600 nm, less than about 400 nm, less than about 200 nm, less than about 100 nm, etc. The average cross-sectional diameter may also be at least about 100 nm, at least about 200 nm, at least about 400 nm, at least about 600 nm, at least about 800 nm, at least about 1 micrometer, at least about 3 micrometers, at least about 10 micrometers, at least about 30 micrometers, at least about 100 micrometers, at least about 300 micrometers, at least about 1 mm, etc. Combinations of any of these are also possible.
In certain aspects, one or more reaction entities may be immobilized relative to the member, for example, on an end portion, a transition portion, or other portion. The reaction entities may be, for example immobilized relative to or fastened directly to an end or transition portion, and/or to one or particles fastened or immobilized relative to the member, e.g., to an end or transition portion of a member. Examples of particles include those discussed above. In some cases, the reaction entities may coat at least a portion of the member, and/or on at least a portion of a particle, if present. Thus, in some cases, for instance, the particles may be partially or completely coated with a layer of reaction entities.
In one set of embodiments, an analyte may be determined via interaction of the analyte with the reaction entity. The term “reaction entity” refers to any entity that can interact with an analyte in such a manner to cause a detectable change in a property, e.g., of a member, such as a chemical property, an optical property, a mechanical property, a vibration property, etc. The reaction entity can comprise a binding partner to which the analyte binds. The reaction entity, when a binding partner, can comprise a specific or a non-specific binding partner of the analyte. For example, the reaction entity may be a chemical or a biochemical, such as a metal, a nucleic acid, an antibody, an aptamer, a sugar, a carbohydrate, a protein, a polymer, catalyst, a quantum dot, etc. As another example, the reaction entity may comprise platinum, which can be used to determine hydrogen. As yet another example, the reaction entity may comprise a hydrogel, which can be used to determine water or humidity.
The binding partner may be a molecule that can undergo binding with a particular analyte, and includes specific, semi-specific, and non-specific binding partners as is known to those of ordinary skill in the art. The term “specifically binds,” when referring to a binding partner (e.g., protein, aptamer, nucleic acid, antibody, etc.), refers to a reaction that is determinative of the presence and/or identity of one or other member of the binding pair in a mixture of heterogeneous molecules (e.g., proteins and other biologics). Thus, for example, in the case of a receptor/ligand binding pair, the ligand would specifically and/or preferentially select its receptor from a complex mixture of molecules, or vice versa. An enzyme would specifically bind to its substrate, a nucleic acid would specifically bind to its complement, an antibody would specifically bind to its antigen. Other examples include, nucleic acids that specifically bind (hybridize) to their complement, antibodies specifically bind to their antigen, and the like. The binding may be by one or more of a variety of mechanisms including, but not limited to ionic interactions, and/or covalent interactions, and/or hydrophobic interactions, and/or van der Waals interactions, etc.
Another aspect of the present invention is generally directed to systems and methods of making members such as those discussed herein. In some cases, for example, members may be produced by etching various materials to produce the shapes and/or sizes discussed herein. The choice of etchant may depend based on the materials forming the member. For example, metals such as copper, iron, nickel, steel, etc. can be etched using acids such as HCl (hydrochloric acid), HNO3 (nitric acid), sulfuric acid (H2SO4), and/or other compounds such as such as ferric chloride (FeCl3) or copper sulfate (CuSO4). As yet another example, silicon or other semiconductor materials can be etched using etchants such as EDP (a solution of ethylene diamine and pyrocatechol), KOH (potassium hydroxide), or TMAH (tetramethylammonium hydroxide). Plastics or polymers such as polymethylmethacrylate, polystyrene, polyperfluorobutenylvinylether, etc., can be etched using KOH (potassium hydroxide), or acids such as those described herein. The etchant may be present in pure form, or present in solution, e.g., in polar solution, at any suitable concentration. Higher concentrations may result in faster etchings, while lower concentrations may result in slower and/or more controlled etchings.
In some cases, a material may be etched by exposing the material to etchant media comprising etchant. The etchant media may also contain other components or phases, e.g., as discussed below. The etchant may be applied to the material using any suitable technique. For example, the etchant may be sprayed, coated, or painted onto the material, or in some cases, a portion of the material may be inserted or submerged into the etchant media, for example, as is shown in
As previously discussed, in some cases, a meniscus, such as a concave meniscus, may form around the partially exposed material. As the etchant etches the exposed material, a portion of the material may thin or become etched away, e.g., to form an end portion or a transition portion. The meniscus may also cling to the material, e.g., due to surface tension or capillary forces, to produce a tapered region of the material.
The material may be removed before etching is completed, e.g., to produce members having shapes and/or sizes such as those discussed herein. Thus, for example, the member may be removed from the etchant media when a portion of the member has been etched to have an average cross-sectional diameter of no more than about 50 micrometers, no more than about 40 micrometers, no more than about 30 micrometers, no more than about 25 micrometers, no more than about 20 micrometers, no more than about 15 micrometers, no more than about 10 micrometers, no more than about 5 micrometers, no more than about 3 micrometers, no more than about 1 micrometer, no more than about 750 nm, no more than about 500 nm, no more than about 250 nm, or no more than about 100 nm, or the like, or other dimensions as discussed herein.
In some embodiments, the material may be removed before etching for a certain period of time. For example, the material may be exposed to the etchant for at least about 1 sec, at least about 5 sec, at least about 10 sec, at least about 30 sec, at least about 1 min, at least about 2 min, at least about 3 min, at least about 5 min, at least about 10 min, at least about 20 min, at least about 30 min, at least about 40 min, at least about 50 min, at least about 60 min, at least about 75 min, at least about 90 min, at least about 120 min, at least about 180 min, at least about 240 min, etc. In some cases, the amount of time may be no more than about 240 min, no more than about 180 min, no more than about 120 min, no more than about 90 min, no more than about 75 min, no more than about 60 min, no more than about 50 min, no more than about 40 min, no more than about 30 min, no more than about 20 min, no more than about 10 min, no more than about 5 min, no more than about 3 min, no more than about 2 min, no more than about 1 min, no more than about 30 sec, no more than about 10 sec, no more than about 5 sec, or no more than about 1 sec. Combinations of any of these times are also possible, for instance, between about 10 minutes and about 30 minutes.
In some cases, the material may be physically removed from the etchant, or the etchant may be washed or rinsed away. For instance, in one embodiment, the material is removed from the etchant media, then washed or rinsed with a rinsing agent, e.g., with water, a base, an aqueous fluid, a polar fluid, a non-polar fluid, or the like. The polar or aqueous fluid may be, for instance, methanol or acetonitrile. In some embodiments, the rinsing agent may be sprayed onto the material, or the material may be partially or completely immersed in a container containing the rinsing agent. In some cases, e.g., as is shown in
For example, in some embodiments, another phase of the etchant media may be provided to control the amount of etching. For instance, as is shown in
In some cases, the material is exposed to a container containing etchant, but the etchant concentration may be altered during the etching process. For instance, as is shown in
In some cases, a plurality of materials may be simultaneously exposed to an etchant, e.g., as described herein. For example, the materials may be individually applied, or an array of such materials may be formed and simultaneously exposed to an etchant, e.g., within an etchant media. As an example, as is shown in
In some cases, one or more particles may be added to the member, e.g. after etching. A variety of particles that can be used, including spherical and non-spherical particles, have been discussed above. In some cases, the particles may be fastened or immobilized to the member via any suitable technique. For instance, in one set of embodiments, e.g., as is shown in
Members such as those discussed herein may be used in a wide variety of applications and uses, according to various aspects of the invention. For example, in one set of embodiments, a member may be used as a probe for a cell. The member may be partially or completely inserted into a cell. For instance, an end portion of the member may be inserted into a cell (e.g., into the cytoplasm of the cell), and used to interrogate or study at least a portion of the cell. In some cases, this may be performed using light-based techniques, for example, if the member is able to transmit light. Thus, a characteristic of the cell may be determined using light propagated through the member. For instance, light may be used to analyze the cell using techniques such as surface plasmon resonance (SPR) (including localized surface plasmon resonance), or other techniques described herein. In some cases, the member may also contain a reaction entity, e.g., immobilized relative to a portion of a member or a particle immobilized relative to a portion of a member, and the reaction entity. Interaction of the reaction entity with an analyte within the cell may be detectable as discussed herein, e.g., due to change in light or vibration.
The cell may be any suitable cell. The cell may be, for example, a human cell, or other mammalian cell. The cell may also be a bacterium or other single-cell organism, a eukaryotic cell, a plant cell, or an animal cell. Any suitable method of inserting the member into the cell may be used. For example, the member may be inserted into the cell using microinjection, micromanipulation, or other techniques known to those of ordinary skill in the art.
As mentioned, in certain embodiments, the member may be used to optically interrogate or study a sample, for example, a cell. In some cases, a characteristic of the cell or other sample, such as the presence or concentration of an analyte, may interact with the member and/or a reaction entity on the member, which can be determined optically. Examples of optical interrogation techniques that may be used include, but are not limited to, fluorescence, phosphorescence, surface plasma resonance, localized surface plasma resonance, Raman spectroscopy, surfaced-enhanced Raman spectroscopy, or the like.
The member may be used to transmit light to and/or from a sample, such as a cell. For instance, as is shown in
In another set of embodiments, the member can be positioned to be in optical communication with an optical component. For instance, the member may be positioned to deliver light to the optical component, or to receive light form the optical component. The optical component may be, for example, a waveguide, an optical sensor, an optical detector, an optical fiber, or the like. In some cases, the optical component may be positioned on a substrate, such as a silicon wafer, and the member used to direct light to or from the substrate.
In addition, it should be understood that other techniques may be used to determine an analyte or a characteristic of a sample, in addition or instead of optical techniques. For example, in another set of embodiments, the member may be cantilevered and mechanically vibrated, and characteristics about the vibration of the member may be determined. For instance, the amplitude and/or frequency of the vibration of the member may be determined, e.g., electrically or optically (for example, using a microscope). The vibrations may be induced using a suitable vibrating device, or in some cases, via ambient vibration or thermal noise. Without wishing to be bound by any theory, it is believed that the binding of analytes to a reaction entity immobilized relative to the member (or to particles immobilized to the member) may alter the vibration characteristics of the member, e.g., its amplitude and/or frequency of vibration, and these characteristics may be used to determine the analyte, e.g., the amount or concentration of analyte. For instance, the binding of analytes to a member may alter the weight or weight distribution of the member, and hence affect its vibration characteristics. Thus, for instance, differences in vibration before and after binding of the analyte may be used to determine the presence and/or concentration of the analyte. Any of the analytes and reaction entities discussed herein may be used in various embodiments. For example, hydrogen may be determined based on binding of hydrogen to platinum, while humidity or moister may be determined based on binding of water to a hydrogel, etc.
In some cases, other characteristics can be determined by determining the vibration characteristics of the member, and/or changes in the vibration characteristics of the member. For instance, in some cases, changes in temperature, electric field intensity, magnetic field intensity, etc. may be determined. For example, in some embodiments, nano-diamond particles may be used to sense electric fields, magnetic fields, or temperatures. For instance, nano-diamond particles may comprise nitrogen vacancy (NV) centers that can be in certain spin states as a function of electromagnetic fields and/or temperatures. Accordingly, changes in electric fields, magnetic fields, or temperature may result in changes in spin state, which can be detected, for example, by determining changes in fluorescence activity of the nano-diamond particles, e.g., using members as discussed herein. In addition, in some embodiments, vibration or motion may be imparted to the member using systems and methods such as piezostacks or AC electric fields.
U.S. Provisional Patent Application Ser. No. 61/991,842, filed May 12, 2014, entitled “Systems and Methods for Making and Using Probes and Other Devices,” by Quan, et al. is hereby incorporated herein by reference.
The following examples are intended to illustrate certain embodiments of the present invention, but do not exemplify the full scope of the invention.
The following examples illustrate a localized surface plasmon resonance (LSPR) fiber tip probe (FTP) system in accordance with certain embodiments of the invention. The following examples also demonstrate label-free detection of intracellular p53. However, the methods described herein may be also widely applicable to other intracellular proteins; p53 is used solely as an example.
The FTP used in this example was a tapered optical fiber that has a sub-5 micrometer length and sub-100 nanometer diameter tip (
A scanning electron microscope (SEM) image of the FTP is shown in
To test for sensitivity, an LSPR-FTP probe was characterized in an in vitro aqueous environment in this example. First, the FTP was used to detect different concentrations of glycerol in water. Solutions of 20%, 40%, 60%, and 80% of glycerol in water were prepared and injected into a microfluidic channel. The FTP was inserted into the channel, and sealed with epoxy. The LSPR signal excited through the fiber coupled with halogen light source was monitored with inverted microscope (Olympus IX71) (
An FTP was used in this example to detect different concentrations of proteins in PBS solution. The gold nanorod on the tip of the FTP was functionalized with a p53 antibody (Santa Cruz sc-126). Different concentrations of p53 (Santa Cruz sc-4246) in PBS were injected into the fluidic channel for 15 minutes, followed by washing with pure PBS.
To study the specificity of the system, various FTPs were functionalized with antibodies of either tumor suppressor p53 or tumor necrosis factor (TNF-α, TNF-alpha), and these were used FTPs to detect p53 and TNF-alpha (
An FTP may offer a unique three-dimensional nanoscale form-factor in accordance with certain embodiments; thus, it may be used, for example, as a minimally invasive bioprobe into cells. This example demonstrates how p53 in HeLa cells dynamically reacted to ultra-violet (UV) exposure and neocarzinostatin (NCS) drug treatment. A commercial anti-p53 to intracellular p53 was first validated by performing western blotting with HeLa cell lysis (
The intensity of UV light source was first calibrated. Live HeLa cells were exposed by different dosage of UV light or different concentrations of NCS. FTP experiments were performed immediately after the treatments. The results of these experiment indicated that different stresses triggered different temporal response of p53. As shown in
As a control experiment, the same procedure was performed on an intact HeLa cell. As shown in
FTP probes such as those discussed in this example may offer certain advantages. First, this is a label-free technology, e.g., free from labels interfering with proteins. Second, the FTP was capable of interrogating single cells, free from cell harvest and cell lysis. Third, the FTP revealed real-time dynamics, and was quantitative. For example, by referring to measurements in the in vitro environment, the p53 concentration could be inferred up to the order of 10 nM under external stress (UV illumination).
Combining the advantages of high selectivity from antibody-antigen recognition and high sensitivity of LSPR, this example demonstrated a novel three-dimensional nanoscale bioprobe for intracellular protein detection. This method may be especially useful for cells and systems that are hard to label, for example, immune cells, neurons, and precious patients' cells and circumstances that require in vivo and in situ detection. While this example uses s a single bioprobe detecting one specific protein in single cells, these approaches may be extended to other systems, e.g., high-throughput multiplexed system, for instance, by using fiber arrays or nanowire arrays.
This example describes, in additional detail, certain procedures used in the above examples.
Fabrication of an FTP. The Fiber Tip Probe (FTP) was fabricated from the widely available glass optical fibers. Glass fibers (SM28, Thorlabs Inc.) were etched with hydrogen fluoride (HF) wet chemistry to taper the tip down to sub-100 nm sizes (
Preparation of MUA-coated gold nanorods. 100 microliters of a 20 mM solution of 11-mercaptoundecanoic acid (11-MUA, Sigma-Aldrich) prepared in ethanol was mixed with 1 mL of cetrimonium bromide (CTAB) capped gold nanorods (Nanopartz Inc.). The mixed solution was sonicated for 90 minutes at 55° C. After keeping the mixed solution at room temperature overnight, sedimentation of the rods was observed. The nanorods were re-immersed in a sonic bath and then the excess MUA was removed using centrifugation at 7000 rpm for 10 minutes. Then, MUA-coated gold nanorods could be readily redispersed in H2O. These nanorods were dispersed on a thin cover glass and one nanorod was picked up by FTP mounted on the micromanipulator (
Conjugate gold nanorod on FTP. A single gold nanorod was conjugated on the sub-100 nm tip of the FTP as follows. The gold nanorods coated with 11-MUA were first dispersed onto a cover-glass and could be observed under dark field (
Localized Surface Plasmon Resonance (LSPR) measurement. To study the effect of orientation to the LSPR of the gold nanorod, two nanorods were attached that were coincidently arranged perpendicular to each other (
Fabrication of PDMS channel. SU-8 (Shipley) was used to pattern a 150 micrometer thick mold on top of a silicon substrate via photo-lithography. A 125 micrometer-wide channel was fabricated in the middle of the flow channel (2 mm by 10 mm) so that the fiber (125 micrometers in diameter at its stem) had room to reside in the middle of the flow channel. The FTP was pasted onto an O2-cleaned glass slide and the PDMS channel was carefully assembled onto the glass slide.
Surface functionalization for in vitro test. 100 mM EDC (Sigma-Aldrich) and 100 nM anti-p53 (Santa Cruz) in 10 mM PBS was flowed into the PDMS channel for 1 hour. EDC molecules reacted to the carboxyl group of MUA molecules, which capped the gold nanorod, and form unstable esters, which reacted to the amine groups on the antibodies. The channel was then flushed with PBS 1× for 30 min to get rid of excess non-specifically bound anti-p53. The FTP was then flowed with various concentrations of p53 for in vitro characterization.
Verification of surface functionalization with UV-Visible spectroscopy. The above surface functionalization procedure was verified using UV-Visible spectrometer (Jasco Inc.). The change of the absorption spectra was measured at each step of the functionalization procedure. First, MUA-capped nanorods were mixed with 100 mM EDC (Sigma-Aldrich) and 100 nM p53 antibody (Santa Cruz) in PBS 1× (pH 7.4) for 1 hour. The resulting nanorods were then collected by centrifugation at 5000 rpm for 5 min and resuspended in a buffer containing 5 mM CTAB. After three rounds of vigorous washing, the collected nanorods were sonicated in 5 mM CTAB solution for 10 minutes. As shown in
Different concentrations of p53 protein were added to the anti-p53 modified gold nanorod solution. Each solution was vortexed for 5 min under room temperature before UV-Visible spectrum measurements. In order to minimize bulk refractive index change by the addition of protein solution into the nanorod solution, a small volume of p53 protein was used from the original p53 stock solution with a high density of proteins (50 micrograms/ml). ˜1 microliter of the p53 stock solution was added to 1 ml of gold nanorods to obtain 1 nM p53. Also, the concentration of p53 was ensured to be sufficiently higher than that of nanorods; the nanorod solution was ˜1010 ml−1, while 1 nM p53 was ˜1012 ml−1.
In vitro p53 detection. Repeated experiments were performed for in vitro detection. The FTP was functionalized with anti-p53 (Santa Cruz). Different concentrations of p53 (Santa Cruz) in PBS were injected into the PDMS channel for 15 minutes, followed by washing with pure PBS.
Intracellular p53 detection. Repeated experiments were performed to demonstrate intracellular p53 detection. An FTP was functionalized with anti-p53. HeLa cells were either exposed to 10 J/m2 of ultra-violet (UV) light, or treated by 400 ng/ml of NCS drug. The FTP was inserted into the cytoplasm of the cell, incubated for 5 minutes, and then retrieved from the cell and measured in the cell culture medium. This insertion, incubation, and measurement were repeated every 30 minutes. Different FTPs were used in each experiment.
Cell culture and immunoblots. Human cervix epithelial HeLa cells (American Type Culture Collection, ATCC) were cultured at 37° C. in DMEM F-12 Medium supplemented with 10% fetal calf serum, 100 U/ml penicillin, and 100 mg/ml streptomycin.
The cells were harvested, lysed, and the total protein concentration was measured (10 mg/mL) by a Bradford assay (Thermo Scintific). The proteins were then separated by electrophoresis on 4-20% Mini-PROTEAN TGX Stain-Free precast gels (Bio-Rad), and transferred to PVDF-membrane (Bio-Rad) by electroblotting. The membrane was incubated with primary p53 monoclonal antibody (Santa Cruz) overnight, washed, and incubated with secondary antibody for 2 hours. Protein levels were then observed by chemoluminiscence after adding SuperSignal West Pico Working Solution (Thermo Scientific) for 5 minutes. Both commercial p53 and lysate of HeLa cells paired well to the commercial anti-p53.
Cell viability test. A fluorometric assay of calcein AM was used, following the suggested protocol (Invitrogen LIVE/DEAD). The cells were probed or loaded, and the positions of those cells were documented by carving out reference marks in the Petri dish using a broken FTP after the experiment. The cells were then incubated for 6 hours, after which they were treated with 2 micromolar of calcein AM in PBS. Fluorescence images were captured with a Nikon Eclipse Ti fluorescence microscope with a LED laser (Thorlabs).
This example describes a fiber tip probe (FTP) system having a nano-diamond sensor. As shown in this example, the sensor may be used for applications such as electric field, magnetic field, or temperature detection.
Diamonds may have a nitrogen vacancy (NV) center, composed of one substitutional nitrogen atom and an adjacent vacancy. The NV may form a ground state spin triplet that can be controlled coherently at room temperature using electromagnetic fields and temperature. NV centers can be excited by an off-resonant 532 nm laser, and subsequently may emit fluorescence with a 637 nm zero-phonon line. The state ms=−1 can be isolated from the state ms=+1 by applying an external magnetic field to induce Zeeman splitting; electric field and temperature shifts ms=0. The ground-state spin splitting around 2.88 GHz, or electron spin resonance dip (
This example describes, in additional detail, the FTP functioning as a mechanical sensor, in accordance with certain embodiments of the invention.
By scanning the AC modulation frequency and analyzing the Fast Fourier Transform (FFT) of the transmitted light through the lens fiber, the resonance frequency of the FTP can be determined. For instance, as is shown in
This mechanical resonance frequency of the fiber may be very sensitive to the mechanical alternation to the fiber. For example, the end portion of the FTP may be coated with an antibody for detection of a protein or other antigen, platinum for detection of hydrogen, or a hydrogel for detection of water (e.g., to determine humidity).
This example shows FTP functioning as an optical guide to characterize micro- to nano-optical devices, in another embodiment of the invention.
Thin nanowire portion of single-ended or double ended FTPs (
While several embodiments of the present invention have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the present invention. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the invention may be practiced otherwise than as specifically described and claimed. The present invention is directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the scope of the present invention.
All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.
The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”
When the word “about” is used herein in reference to a number, it should be understood that still another embodiment of the invention includes that number not modified by the presence of the word “about.”
The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.
As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.
As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.
It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.
In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/991,842, filed May 12, 2014, entitled “Systems and Methods for Making and Using Probes and Other Devices,” by Quan, et al., incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US15/30125 | 5/11/2015 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61991842 | May 2014 | US |
