This application claims the benefit of Taiwan Patent Application No. 107147522, filed on Dec. 27, 2018, at the Taiwan Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference.
The present invention is related to a sensing system and method, and in particular, a quasi-volumetric sensing system and method.
At present, there are products and services provided by incorporating biochemical reactions with micro-analysis with the micro-electromechanical (MEM) system, wherein trace amount of reagents and samples are used, and the signals differentiated from background signals are obtained using the specificity and sensitivity of specific molecules in the sample. Furthermore, parameters, e.g. the sample volume, and the level of specific molecules in the sample are finally obtained by detecting signals via optical and electromagnetic methods in the MEM system. These parameters are further provided to users or medical professionals.
Most of the current chips are designed to have a reaction zone with a sealed cavity so that the reaction volume is fixed. However, this reaction zone will cause a problem with the washing step which makes it difficult to remove the signals of non-reactive molecules during the biochemical reaction process. Therefore, this chip can only be used in an uncomplicated single-step reaction. If multi-step reactions are desired to be performed with this chip, precisely quantifying tools are essential, which limits the efficacy and usage diversity of the chip.
It is therefore the Applicant's attempt to deal with the above situation encountered in the prior art.
To overcome problems in the prior art, the present invention provides a chip, device or system having a microstructure surface. The reaction fluid is distributed on the chip without essentially configuring channels or covering a lid to let the channels become the seal channels. The photolithography process technique is used in the present invention, short-range order (SRO) units with different specifications and long-range order (LRO) order are designed, and thus the purpose of adjusting the volume of the reaction fluid is achieved. That is to say, the reaction fluid in the present invention still can be distributed on the chip having seal channels or the opened surfaces. For instance, the reaction fluid fills the seal channels and then is removed therefrom or the fixed volume of the reaction fluid flows through the channels, the SRO units within the channels also can be used to retain the fluid with a specific volume. In addition, macromolecules, e.g. antibodies, complements, receptor proteins, aptamers, oligosaccharides and oligonucleotides, are attached to the microstructures to couple to specific molecules in the reaction fluid so as to measure data of the specific molecules. In the present invention, it is only needed to use trace amounts of reagents, samples or reaction fluids (analytes) in the applications, such as a biosensor, biochip or high-throughput screen platform.
Thus, the present invention discloses a device for quantifying a volume to be reacted in a liquid sample, including a carrier, a plurality of signal detection units and a processor. The carrier includes a surface and a plurality of SRO units disposed on the surface, wherein each of the plurality of SRO units includes a first area and a plurality of protrusions distributed on the first area, at least one of the plurality of protrusions is configured to contact a droplet having a specific volume and a first parameter, and the droplet originates from the liquid sample. Each of the plurality of signal detection units is configured to detect the respective first parameter. In addition, the processor is coupled to the plurality of signal detection units and configured to calculate the volume to be reacted according to the first parameter and a formula (I) as follows:
where V is the volume to be reacted, Vi is the specific volume, θ is a contact angle formed between the droplet and the surface, a is an area within the first area, and n is the number of the plurality of SRO units.
In some embodiments, there is a hydrophobic surface between any adjacent two of the SRO units within the surface. In some embodiments, the plurality of SRO units are arranged to form an array on the surface, the array is an LRO unit having a first and a second ends to form a path between the first and the second ends, and the path represents a gradient of hydrophilicity. In some embodiments, the droplet on the carrier is driven by a force, and moves from the first end to the second end so as to remove a redundant liquid from the droplet.
In some embodiments, the device further includes an inlet and an outlet, and the inlet and the outlet are configured at the same end or at two different ends of the carrier. In some embodiments, the device further includes a plurality of first specific molecules having a first part thereof being configured on the plurality of protrusions, wherein the droplet includes a plurality of second molecules, to and with which the plurality of first molecules are respectively specific and coupled.
In some embodiments, each of the plurality of signal detection units is further configured to detect signals generated when the plurality of first molecules are coupled with the plurality of second molecules. In some embodiments, the processor is further configured to calculate a second parameter of the plurality of second molecules in the liquid sample according to the signals, and the second parameter is at least one selected from the group consisting of the concentration of the second molecules, the number of the second molecules and the viscosity of the droplet. In some embodiments, the plurality of first molecules have a second part thereof configured on the surface.
The present invention further discloses a method for quantifying a volume to be reacted in a liquid sample by a chip, wherein the chip includes a carrier, a plurality of SRO units on the carrier, and a plurality of signal detection units electrically connected to each of the plurality of SRO units, and each of the plurality of SRO units includes a plurality of protrusions being distributed thereon. The method includes: providing the liquid sample; applying the liquid sample on the carrier to enable at least one of the plurality of protrusions to contact a droplet having a specific volume and a first parameter, wherein the droplet originates from the liquid sample; detecting the first parameter with a respective one of the plurality of signal detection units; and calculating the volume to be reacted according to the first parameter a formula (I) as follows:
where V is the volume to be reacted, Vi is the specific volume, θ is a contact angle formed between the droplet and the surface, a is an area within the first area, and n is the number of the plurality of SRO units.
In some embodiments, there is a hydrophobic surface between any adjacent two of the SRO units within the surface, the plurality of SRO units are arranged to form an array on the surface, the array is an LRO unit having a first and a second ends to form a path between the first and the second ends, and the path represents a gradient of hydrophilicity.
In some embodiments, the method further includes: applying a force on the droplet to enable the droplet to move from the first to the second ends so as to remove a redundant liquid from the droplet. In some embodiments, the force is one selected from the group consisting of mechanical force, electromagnetic force, capillary force, hydrophilicity, hydrophobicity and the combination thereof. The mechanical force is one of gravity and waves generated from the piezoelectric effect.
The present invention further discloses a quasi-volumetric sensing system for a liquid sample which includes: a carrier including a surface; and a plurality of SRO units configured on the surface, wherein each of the plurality of SRO units includes a plurality of areas each of which includes a plurality of protrusions, and a distance between any adjacent two protrusions in one area is different from that in another area, wherein the liquid sample is applied to run across the plurality of SRO units to enable at least one droplet from the liquid sample to be retained on at least one of the plurality of protrusions.
In some embodiments, the at least one droplet includes a first parameter and a specific volume, the liquid sample includes a plurality of molecules having a specific concentration, and the quasi-volumetric sensing system further includes: a plurality of signal detection units, each of which is electrically connected to a respective one of the plurality of SRO units to detect the respective first parameter; and a processor coupled to the plurality of signal detection units and configured to calculate the specific concentration according to the first parameter, wherein the sum of all of the specific volumes is a volume to be reacted, the specific volumes are determined by a structure of the plurality of SRO units, and the volume to be reacted is obtained according to a formula (I) as follows:
where V is the volume to be reacted, Vi is the specific volume, θ is a contact angle formed between the droplet and the surface, a is an area within the first area, and n is the number of the plurality of SRO units.
The present invention further discloses a system for sensing a liquid sample, including: a carrier including a surface; a plurality of SRO units disposed on the surface and including a plurality of areas; a plurality of structures of different heights disposed in each of the plurality of areas, wherein each of the plurality of structures is concavely or convexly formed on the surface; and a plurality of molecules disposed on each of the plurality of structures and configured to sense the liquid sample, wherein the plurality of areas include a first area and a second area, any adjacent two of the plurality of structures in the first area have a first distance, any adjacent two of the plurality of structures in the second area have a second distance, and the first distance is different from the second distance.
In some embodiment, the plurality of structures are configured to increase a surface area of the surface.
The present invention further discloses a quasi-volumetric sensing system for sensing a liquid sample, wherein the liquid sample includes a plurality of molecules having a concentration, and the system includes: a carrier including a surface; a plurality of SRO units disposed on the surface and including a plurality of areas; a plurality of structures of different heights disposed in each of the plurality of areas, wherein each of the plurality of structures is concavely or convexly formed on the surface; a plurality of molecules disposed on each of the plurality of structures and configured to sense the liquid sample, wherein the liquid sample includes a plurality of droplets having a parameter, and each of the droplets is retained by at least one of the plurality of structures; a signal detection device electrically connected to the plurality of SRO units and configured to detect the parameter; and a processor coupled to the signal detection device and configured to calculate the concentration using the parameter.
The objectives and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed descriptions and accompanying drawings.
The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of the preferred embodiments of this invention are presented herein for purpose of illustration and description only; they are not intended to be exhaustive or to be limited to the precise form disclosed.
In the present invention, the photolithography process technique is used to design the geometrically structural features for SRO units and LRO units on a chip surface so that liquid samples can be carried by the SRO/LRO units on the chip surface. SRO units are reaction units and have microstructures with plural protrusions. The microstructure protrusions are structures which can provide high aspect ratio, and reserve or enlarge enough surface area on the condition that the area of plane is not increased. The changes on the structural and dimensional features of the microstructure protrusions can modify the wettability of the liquid sample on the chip so as to control the volume of the retained liquid sample or droplets on the chip surface. The distance between protrusions is modified via the photolithography process technique so as to control the contact angle of the carried liquid sample or droplet. Furthermore, the specific volume of the droplet can be calculated via the horizontal surface area that plural protrusions are distributed on the surface. The specific volume of the droplet which is calculated by the unit pattern (with the same geometrically structural features) is fixed so as to achieve the quasi-volumetric effect. The quasi-volumetric method of the present invention can be performed on the opened surface of the quasi-volumetric chip, device or sensing system. The design of a cavity or a sealed channel is not essential.
The plural SRO units of the present invention can be arranged as an array on the chip surface to form a LRO unit. The array can be a regular array, including but not limited to a triangle array, a square array, a rectangular array, a polygonal array and a circular array, or an irregular array. In addition to the area for the SRO units and the LRO unit, the chip surface can be designed as a hydrophobic surface. Thus, after a liquid sample or droplets move on the chip surface, only the SRO units and/or the LRO unit can retain the liquid sample or droplets. The driving force to control the movement of the liquid sample or droplets on the chip surface includes, but is not limited to, mechanic force (gravity or waves generated by piezoelectric effect), electromagnetic force, capillary force, hydrophilicity and/or hydrophobicity. When the intensity of the driving force is adjusted to be smaller than the wettability and adsorption of the SRO units, the redundant liquid sample will be removed. However, the retention of the liquid sample or droplets on the SRO units is not affected.
Because the chip of the present invention is an open chip and does not have any cavity or specific channel, multi-step reactions can be performed on the chip compared to conventional techniques. Furthermore, reactant or washing agent can be used to remove the redundant liquid sample or droplets and interfering molecules by applying driving force, so that the measured signals are more real and precise. In addition, the open chip of the present invention can be repeatedly used to measure the same or other liquid sample after washing.
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where V is the volume to be reacted, Vi is the specific volume, θ is a contact angle formed between the droplet and the surface, a is an area within the first area, and n is the number of the plurality of SRO units.
The specific volume of the droplet also can be referred to parameters in Derrick et al. (Determination of contact angle from contact area of liquid droplet spreading on solid substrate, Leonardo Electronic Journal of Practices and Technologies, 2007, 6(10): 29-38) or other equations, wherein the contact radius of the droplet is R(t), the height of the droplet is h(t)=½ R(t)θ, the area that the droplet contacts the plane is a=½πR(t), the volume of the droplet is V=½ πh(t)R(t)2, and t is time.
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In the present invention, the liquid sample can be directly applied on the carrier 2, or the carrier 2 can be directly merged into a container which includes the liquid sample so that the liquid sample or the droplet 8 may attach on the carrier 2. In the scheme that the carrier is directly merged into the container, the carrier is merged and then picked up so that the liquid sample or droplets attach on the carrier. The operator can directly merge the carrier into a container including another liquid sample, or merge the carrier into a container including the washing solution (such as water, phosphate buffered saline, and so on) or a container including an antibody or reactant solution. The number or sequence of the containers and the contained solutions can be modified depending on the operator's demand. Alternatively, inlet 11 and outlet 12 can be configured on the carrier (as shown in
A surface acoustic wave (SAW) element 17 also can be configured on the carrier 2 of the quasi-volumetric device 1 in
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Therefore, the quasi-volumetric device of the present invention can retain and measure the fixed volume of the droplets by the quasi-volumetric method.
In addition to the quasi-volumetric quantification for the reaction volume, the level or concentration of specific molecules in the liquid sample or droplets is detected.
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Various species of SRO units can be configured on the same quasi-volumetric device using the photolithography process technique, and each SRO unit is arranged as an LRO unit by way of specific number and array. Furthermore, the specific first molecules are connected to the protrusions and the surface of the SRO unit, and a subject's blood, serum, urea or other components in the body fluid or the components in one liquid material is detected. Please refer to
Alternatively, on another carrier 2, the antibodies specific to molecules A, B and C (with the level in the blood being A<B<C) respectively are connected to the protrusions of the SRO units in zones “a”, “b” and “c”. As mentioned above, signal detection unit detects the signal intensity of the antibodies against the molecules A, B and C so as to calculate the level of the molecules A, B and C in the serum.
After the antibodies on the quasi-volumetric device are bonded with the molecules in the liquid sample, other biochemical reactions can be further processed, such as enzyme-linked immunosorbent assay (ELISA).
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The single quasi-volumetric device having different sizes and densities of protrusions of SRO units in
In one embodiment of the present invention, the liquid sample enters into the quasi-volumetric device through the inlet and leaves from the outlet, and droplets are retained on the SRO units. Please refer to
In conclusion:
In the system, device and method disclosed in the present invention, the configuration of the inlet and the outlet are not essential, but the liquid sample can flow to the SRO units via the inlet and automatically distribute to the SRO units. The determination of total volume of the liquid sample or the droplets on the SRO units is called quasi-volumetric quantification. Therefore, the determined electronic or optical signals from all SRO units are added up, and thus variance (tolerance) is decreased and sensitivity is increased.
Because the signals of each SRO units are independently collected by the plural signal detection units, thus the question that the defects in the chip affect the subsequent reading values in the prior art would not occur. If there is only a few defects in a qualified chip device but most SRO units can be normally operated, the measurement for the chip device still is not affected so as to obtain the high reliability of the measurement results.
While the invention has been described in terms of what is presently considered to be the most practical and preferred Embodiments, it is to be understood that the invention need not be limited to the disclosed Embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
Number | Date | Country | Kind |
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107147522 | Dec 2018 | TW | national |
Number | Name | Date | Kind |
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20140287423 | Nurse | Sep 2014 | A1 |
Number | Date | Country |
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2013063230 | May 2013 | WO |
Entry |
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Njobuenwu, Derrick O. et al., paper entitled “Determination of Contact Angle from Contact Area of Liquid Droplet Spreading on Solid Substrate”, Leonardo Electronic Journal of Practices and Technologies, Issue 10, Jan.-Jun. 2007, 10 pages. |
Sommers, Andrew et al., paper entitled “Calculating the Volume of Water Droplets on Topographically-Modified, Micro-Grooved Aluminum Surfaces”, Purdue University, 2008 Int'l. Refrigeration and Air Conditioning Conference, 9 pages. |
Number | Date | Country | |
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20200206731 A1 | Jul 2020 | US |