This application claims priority from Korean Patent Application No. 10-2007-0014935 filed on Feb. 13, 2007 in the Korean Intellectual Property Office, the disclosure of which is hereby incorporated by reference herein in its entirety.
1. Technical Field
The present disclosure relates to a microarray and more particularly, to a microarray with improved light detection and a method of producing the same.
2. Description of the Related Art
As the genome project advances, genome nucleotide sequences of a variety of organisms have been found, which has thereby increased the interest in using microarrays. The microarray is extensively used to perform gene expression profiling and genotyping to detect mutation and polymorphism such as, for example, single nucleotide polymorphism (SNP), to analyze protein and peptide, to perform screening of potential drugs, and to develop and produce new drugs.
The microarray includes a plurality of probes that is fixed to a substrate. The probes are directly fixed through spotting, or being synthesized in situ by using photolithography to perform the fixing. The probes are made of a substance capable of being mixed with a target substance. If a target substance containing a fluorescent substance is mixed with a probe, the fluorescent substance is to remain on the microarray. The fluorescent substance is excited to emit light so as to determine the presence or non-presence of mixing as well as the degree thereof.
Like other microelectronic fields, the recent interest in microarrays comes from the fact that more information can be obtained from smaller substrates. For this to occur, the amount of fixed probes per unit area should be increased and a high rate of light detection in relation to mixed amounts should also obtained. Significant effort has been made to achieve this, but no satisfactory method satisfying the above-mentioned requirements has been suggested in the conventional art.
Exemplary embodiments of the present invention provide a microarray with an integrated probe density and high rate of light detection.
Exemplary embodiments of the present invention provide a method of producing a microarray with an integrated probe density and a high rate of light detection.
In accordance with an exemplary embodiment of the present invention, a microarray is provided. The microarray includes a substrate, a plurality of fine particles disposed on the substrate at regular intervals, and a plurality of probes coupled with the fine particles.
In accordance with an exemplary embodiment of the present invention, a method of producing a microarray is provided. The method includes providing a substrate, disposing a plurality of fine particles on the substrate so that the fine particles are disposed at regular intervals, and coupling a plurality of probes with the fine particles.
Details of other exemplary embodiments are included in the detailed description and drawings.
Exemplary embodiments of the present invention can be understood in more detail from the following description taken in conjunction with the attached drawings in which:
The present invention may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein.
Spatially relative terms, such as “below”, “beneath”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. Like reference numerals refer to like elements throughout the specification.
Exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings hereinafter.
With reference to
The substrate 110 may be, for example, a flexible or rigid substrate. Examples of the flexible substrate may include but are not limited to membranes or plastic films made of nylon or nitrocellulose. Examples of the rigid substrate may include but are not limited to a silicon substrate or a transparent glass substrate of soda-lime glass. In the case of the silicon substrate or the transparent glass substrate, nonspecific bonding hardly occurs during a hybridization process. Additionally, the silicon substrate or the transparent glass substrate may be beneficial because the process producing various thin films or photolithography process typically used to produce semiconductor devices or LCD panels can be applied to them without modification.
The substrate 110 may include a probe cell region (CR) and a probe cell isolation region (CIR). The probe cell region (CR) and the probe cell isolation region (CIR) of the substrate 110 may not be physically distinguishable on their own but distinguished according to how the probe 130 is disposed. For example, the probe 130 is disposed in the probe cell region (CR), but not in the probe cell isolation region (CIR). The probe cell region (CR) may be divided by the probe cell isolation region (CIR) into a plurality of regions, that is, the probe cell region (CR) is defined by the probe cell isolation region (CIR) which surrounds it.
A plurality of fine particles 120 is disposed in the probe cell region (CR) of the substrate 110. The fine particles 120 may have, for example, a spherical or oval shape physically. In the case that the fine particle 120 has a physically spherical shape, the fine particle 120 may be a nanoparticle or a microparticle about 50 to about 10,000 nm in diameter (2r). In the case that the fine particle 120 is roughly oval, the fine particle 120 may be a nanoparticle or a microparticle with a major axis of about 50 to about 10,000 nanometers (nm). For example, each fine particle 120 may have an identical diameter (2r) or major axis. The fine particles 120 may be made of, for example, inorganic substances such as silicon oxides (for example, SiO2) or titanium oxides (TiO2), methyl methacrylate, styrene, dimethyl siloxane, vinyl alcohol, hydroxy methacrylate, or a polymer or copolymer thereof. Furthermore, the fine particle 120 may be made of two or more substances out of the above-mentioned substances.
The fine particles 120 may be, for example but not limited to, disposed to form a single layer. Furthermore, the fine particles 120 are disposed at regular intervals (L). In connection with this, the interval (L) means the distance between the centers of adjacent fine particles 120. By this reason, the fine particles 120 are unidirectionally disposed so that the interval (L) between adjacent fine particles 120 can be constant. For example, as shown in
As shown in
Furthermore, the fine particles 120 may be spaced out at regular intervals (L). The spacing of fine particles means that adjacent fine particles 120 are not in contact with one another and space is provided between the adjacent fine particles. Therefore, as shown in
The fine particles 120 that are spaced out at regular intervals (L) may constitute a photonic crystal structure. That is, as shown in
The fine particles 120 that constitute the photonic crystal structure may be disposed to make the distance (L) between the centers of the fine particles 120 fall in the range between about 150 to about 20,000 nm. For example, the distance (L) between the centers of adjacent fine particles 120 that constitute the photonic crystal structure may be calculated using the following Equation.
In the above Equation, L is the distance between the centers of the adjacent fine particles, λ is the wavelength of detected fluorescent light, and n is the natural number.
In the case that the above-mentioned Equation is satisfied, the wavelength of detected light becomes fully amplified. Therefore, the distance (L) between the centers of adjacent fine particles 120 may be determined according to the wavelength (λ) of detected fluorescent light. The wavelength (λ) of detected fluorescent light may be, for example but not limited to, about 300 to about 600 nm. Meanwhile, the distance (L) between the centers of adjacent fine particles 120 does not strictly depend on the above-mentioned Equation. However, the Equation is just an example to show that the closer the distance gets to the Equation, the better degree of amplification can be obtained.
Each of the fine particles 120 may have a functional group capable of being coupled with the probe 130 on the surface thereof, and may be directly coupled with a plurality of probes 130 through the functional group or through the functional group and the linker 140.
The probe 130 may be, for example, an oligomer probe. Here, the term “oligomer” means the polymer that is made of two or more monomers covalent bonded to one another with a molecular weight of about 1000 or less. The oligomer may include about 2 to about 500 monomers. For example, the oligomer may include about 5 to about 30 monomers. However, in the oligomer of exemplary embodiments of the present invention, the molecular weight is not limited to the above-mentioned numerical value, but may include any oligomer known in the art.
Examples of the monomer of the oligomer probe may include but are not limited to nucleosides, nucleotides, amino acids, or peptides.
Nucleosides and nucleotides may include but are not limited to a known purine or pyrimidine base, or include methylated purine or pyrimidine, or acylated purine or pyrimidine. Examples of the base may include but are not limited to adenine (A), guanine (G), thymine (T), cytosine (C), or uracil (U). Furthermore, nucleosides and nucleotides may include but are not limited to known ribose or deoxyribose saccharides, or include but are not limited to modified saccharides in which one or more hydroxyl groups are substituted by halogen atoms or aliphatics or to which the functional group such as ether or amine is bonded.
The amino acid may be, for example, an L-, D-, or nonchiral-type amino acid which is found in nature. Alternatively, the amino acid may be a modified amino acid or an analog of the amino acid.
The peptide is a compound made by, for example, amide bonding between a carboxyl group of an amino acid and an amino group of another amino acid.
Therefore, the probe (oligomer probe) 130 may be made of, for example, two or more nucleosides, nucleotides, amino acids, and peptides.
In the case that the linker 140 mediates to couple the fine particles 120 with the probe 130, the linker 140 may be made of substances containing both functional groups capable of being coupled with the fine particles 120 and functional groups capable of being coupled with the probe 130. The linker 140 may work to provide a spatial margin necessary for mixing and for this, the length of the linker 140 may be, for example but not limited to, about 6 to about 50 atoms.
Meanwhile, the fine particles 120 may remain in the probe cell isolation region (CIR) of the substrate in the exemplary embodiments of the present invention. In this case, however, the probe 130, for example, should not be coupled with the fine particles 120 in the probe cell isolation region (CIR).
As described above, the fine particle 120 is formed to have the sphere or oval shape and the probe 130 is coupled with the functional group that is provided on the surface of the fine particle 120. Thus, the probe 130 may be coupled with a portion of the surface of the fine particle 120 other than the surface facing the substrate 110. That is, as shown in
In addition, as described in the above, as the fine particles 120 constitute the photonic crystal structure, the intensity of detected light may increase according to the degree of mixing. Therefore, mixing can be readily detected even when a relatively small amount of probe 130 is integrated.
Microarrays according to the other exemplary embodiments of the present invention will be described hereinafter. A description may be omitted or briefly given of the same structure and constitution as the embodiments of
First, the microarray 102 shown in
The first mask pattern 210 may be made of, for example but not limited to , a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer or a photoresist layer in the subsequent process as long as interaction does not occur.
The microarrays according to some exemplary embodiments of the present invention may include a recess pattern on the surface of the substrate. For example, as shown in
The microarray 104 of the embodiment of
Unlike the embodiment of
A method of producing the microarrays will be described hereinafter.
First, the method of producing the microarrays shown in
With reference to
With reference to
For example, the fine particle precursors 120a may have a spherical shape and identical diameter. For example, they may be about 150 to about 20,000 nm in diameter. However, cases where the fine particle precursors 120a are an oval shape are not excluded from the present exemplary embodiment.
For example, the fine particle precursors 120a may be dispersed in a solvent such as alcohol to be provided as a dispersion solution. The dispersion concentration may be, for example, about 0.1 to about 10%. In the case where the fine particle precursors 120a are provided as a dispersion solution, for example, a spin coating process or a slit coating process may be used. In the case where the spin coating process is performed, the coating may be performed at the speed of about 200 to about 1,000 rpm.
For example, the fine particle precursors 120a should be provided as a dispersion solution under the condition that they are disposed to form a single layer. Sometimes, the spin coating is useful for the control of the disposal of the fine particle precursors 120a in a single layer.
The next step is to agglomerate the fine particle precursors 120a through annealing. The annealing temperature may be, for example, about 300 to about 1,000° C. The annealing time may be, for example, about 5 to about 24 hours. In the present exemplary embodiment of the present invention, the annealing temperature and time may be about 500° C. and about 12 hours, respectively.
With reference to
In some exemplary embodiments, the fine particle precursors 120a of the probe cell region (CR) agglomerate towards the center of the probe cell region (CR) between the first mask patterns 210. Therefore, the fine particle precursors 120a may not be present in the periphery of the first mask patterns 210. As described in the above, when distinguishing the probe cell region (CR) from the probe cell isolation region (CIR) by the presence or non-presence of probes coupled with fine particles, the periphery of the first mask pattern 210 where the fine particle precursors 120a are not present may be considered the probe cell isolation region (CIR). That is, the probe cell isolation region (CIR) may include an exposed portion not being covered with the first mask pattern 210.
With reference to
Meanwhile, to keep the first mask pattern 210 on the resulting structure like the microarray 102 of
With reference to
The shape of the fine particle 120 that is formed through the size reduction of the fine particle precursor 120a may be, for example, a sphere or oval having the diameter or major axis of about 50 to about 10,000 nm. For example, the sizes of the fine particles 120 be the same as each other. The fine particles 120 that are reduced in size do not contact with the neighboring fine particles 120 but are spaced apart from each other. In the case where the distances between the centers of the adjacent fine particle precursors 120a are the same as each other, the distances between the centers of the adjacent fine particles 120 that are reduced in size are the same as each other, the fine particles 120 are disposed at regular intervals. Therefore, the distance (L) between the centers of the adjacent fine particles 120 may be substantially the same as the diameter of the fine particle precursor 120a. That is, the distance (L) between the centers of the adjacent fine particles may be about 150 to about 20,000 nm.
Then, air, which has a refractive index different from that of the fine particles 120 occupies the space between the particles. Such fine particles 120 and space structure constitute the photonic crystal structure which amplifies the intensity of detected light. The minimum width of space, that is, the minimum distance between adjacent fine particles, may be about 10,000 nm or less. Meanwhile, in the case that the solvent coming from the dispersion solution of the find particle precursors 120a selectively remains on the substrate 110 in the present process or the subsequent process, the remaining solvent may be removed using, for example, the spin dry process.
With reference to
With reference to
The present exemplary embodiment is substantially identical with that of
With reference to
With reference to
As shown in
Meanwhile, the microarray 105 of
According to the microarrays obtained from the exemplary embodiments of the present invention, it is possible to couple a large number of probes per unit area because the probes are coupled with the surfaces of the fine particles in either a sphere or an oval. Furthermore, as the fine particles constitute the photonic crystal structure, the detected light intensity increases according to the degree of mixing. Therefore, even with a relatively small amount of integrated probes, mixing can be readily detected.
Having described the exemplary embodiments of the present invention, it is further noted that it is readily apparent to those of reasonable skill in the art that various modifications may be made without departing from the spirit and scope of the invention which is defined by the metes and bounds of the appended claims.
Number | Date | Country | Kind |
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10-2007-0014935 | Feb 2007 | KR | national |