Patent Application
20190011438
The present invention relates to a biosensing device and a method of fabricating the same, and more particularly, to a biosensing device having an electrode structure, and a method of fabricating the same.
Many test methods used to diagnose diseases are based on color change, fluorescence, etc. due to enzyme reaction, but currently, immunoassay methods using immune reaction between antigens and antibodies are also used. Conventional immunoassay mostly uses optical measurement methods based on catalytic reaction of enzyme and optical labeling. These methods require complicated procedures by experienced laboratory researchers, high-priced and large-sized analysis devices, and long analysis times.
The present invention provides a biosensing device and a method of fabricating the same, by which performance of a sensing membrane may be maximized, an analysis time may be reduced, and a low cost may be required. However, the scope of the present invention is not limited thereto.
According to an aspect of the present invention, there is provided a biosensing device including unit cells each including a source electrode and a drain electrode spaced apart from each other, a sensing membrane for forming a channel between the source and drain electrodes, a gate electrode spaced apart from the sensing membrane, and a dam structure surrounding at least parts of an edge of the sensing membrane and made of an insulator, wherein the dam structure is configured to contain a precursor solution to be solidified to form the sensing membrane.
The sensing membrane may include carbon nanotubes (CNT), graphene, molybdenum disulfide (MoS2), or phosphorene.
At least parts of the dam structure perpendicular to a direction proceeding from the source electrode toward the drain electrode may be provided only on the source and drain electrodes without being provided outside the source and drain electrodes.
A width of the dam structure perpendicular to the direction proceeding from the source electrode toward the drain electrode may be less than a width of the source or drain electrode.
Each of at least parts of the dam structure parallel to a direction proceeding from the source electrode toward the drain electrode may have an end provided on the source electrode and another end provided on the drain electrode.
A length of the dam structure parallel to the direction proceeding from the source electrode toward the drain electrode may be greater than a distance between the source and drain electrodes.
A solidification density of the sensing membrane may be higher in a region adjacent to the dam structure compared to a region far apart from the dam structure.
The unit cell may further include a receptor attached onto the sensing membrane and capable of binding to a target material.
The sensing membrane may be made of a material that is variable in resistance depending on the receptor and a target material bound to the receptor.
The receptor may be attached onto the sensing membrane by a functional group, and may include at least one selected from a group consisting of enzyme-substrate, ligand, amino acid, peptide, aptamer, protein, nucleic acid, lipid, and carbohydrate.
The functional group may include at least one selected from a group consisting of an amine group, a carboxyl group, and a thiol group.
The target material may be at least one selected from the group consisting of a protein, a peptide, an aptamer, a nucleic acid, an oligosaccharide, an amino acid, a carbohydrate, a dissolved gas, a sulfur oxide gas, a nitrogen oxide gas, a residual pesticide, a heavy metal, and an environmentally harmful substance.
According to another aspect of the present invention, there is provided a method of fabricating a biosensing device, the method including a first step, for preparing a structure including a source electrode and a drain electrode spaced apart from each other, a second step, for forming a dam structure across at least a gap region between the source and drain electrodes to contact the source and drain electrodes, by using an insulator, and a third step, for forming a sensing membrane for forming a channel between the source and drain electrodes, on an inner region of the dam structure including at least a part of the gap region between the source and drain electrodes, by coating a precursor solution on the inner region of the dam structure and then solidifying the precursor solution.
The sensing membrane may include carbon nanotubes (CNT), graphene, molybdenum disulfide (MoS2), or phosphorene.
In the second step, at least parts of the dam structure perpendicular to a direction proceeding from the source electrode toward the drain electrode may be provided only on the source and drain electrodes without being provided outside the source and drain electrodes.
In the second step, a width of the dam structure perpendicular to the direction proceeding from the source electrode toward the drain electrode may be less than a width of the source or drain electrode.
In the second step, each of at least parts of the dam structure parallel to a direction proceeding from the source electrode toward the drain electrode may have an end provided on the source electrode and another end provided on the drain electrode.
In the second step, a length of the dam structure parallel to the direction proceeding from the source electrode toward the drain electrode may be greater than a distance between the source and drain electrodes.
As described above, according to some embodiments of the present invention, a biosensing device and a method of fabricating the same, by which performance of a sensing membrane may be maximized, an analysis time may be reduced, and a low cost may be required, may be provided. However, the scope of the present invention is not limited to the above-described effect.
Hereinafter, the present invention will be described in detail by explaining embodiments of the invention with reference to the attached drawings. Throughout the specification, it will be understood that when an element, such as a layer, a pattern, a region, or a substrate, is referred to as being “on” another element, it may be directly on the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.
In the drawings, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, the embodiments of the invention should not be construed as limited to the particular shapes of regions illustrated herein, but are to include deviations in shapes that result, for example, from manufacturing. The thicknesses or sizes of layers may be exaggerated for clarity of explanation, and like reference numerals denote like elements.
Referring to
The gate electrode 160 is spaced apart from the source and drain electrodes 140 and 150. The gate electrode 160 may be electrically insulated from the sensing membrane 190 by an insulating member 170 provided between the sensing membrane 190 and the gate electrode 160.
The shapes and locations of the gate electrode 160 and the insulating member 170 in
The receptor 195 may be attached onto the sensing membrane 190 by a functional group. The receptor 195 may include at least one selected from the group consisting of, for example, an enzyme substrate, a ligand, an amino acid, a peptide, an aptamer, a protein, a nucleic acid, a lipid, and a carbohydrate. The functional group may include at least one selected from the group consisting of, for example, an amine group, a carboxyl group, and a thiol group. The target material may include at least one selected from the group consisting of, for example, a protein, an aptamer, a peptide, a nucleic acid, an oligosaccharide, an amino acid, a carbohydrate, a dissolved gas, a sulfur oxide gas, a nitrogen oxide gas, a residual pesticide, a heavy metal, and an environmentally harmful substance.
The sensing membrane 190 may be made of a material that can vary in resistance depending on the receptor 195 and a target material bound to the receptor. The material of the sensing membrane 190 may include, for example, carbon nanotubes (CNT), graphene, molybdenum disulfide (MoS2), or phosphorene. In the biosensing device according to a modified embodiment of the present invention, the sensing membrane 190 may be made of a material that can vary in resistance by reacting directly with the above-described target material without interposing the receptor 195.
The sensing membrane 190 is formed by supplying a liquid-state precursor solution to a region including a space between the source and drain electrodes 140 and 150, and solidifying the precursor solution. The solidifying process may include at least one process selected among natural drying, heat drying, and fan drying.
The dam structure 200 made of an insulator may contain the liquid-state precursor solution supplied to form the sensing membrane 190. While the precursor solution supplied to the region including the space between the source and drain electrodes 140 and 150 is being solidified, the dam structure 200 may allow the precursor solution to stay only in a desired region and not to flow to an undesired region.
Referring to
In the biosensing device according to an embodiment of the present invention, at least parts of the dam structure 200 may include second structures 200b extending in a direction perpendicular to the direction proceeding from the source electrode 140 toward the drain electrode 150 (e.g., a y-axis direction), and provided only on the source and drain electrodes 140 and 150 without being provided outside the source and drain electrodes 140 and 150. For example, ends of the second structures 200b may be provided on the source and drain electrodes 140 and 150 without being provided outside the source and drain electrodes 140 and 150. A width Y1 of the dam structure 200 perpendicular to the direction proceeding from the source electrode 140 toward the drain electrode 150 (e.g., the x-axis direction) may be less than a width Y2 of the source or drain electrode 140 or 150.
In the biosensing device according to an embodiment of the present invention, the dam structure 200 may include both of the first and second structures 200a and 200b. For example, the dam structure 200 may be a rectangular structure in which a pair of first structures 200a spaced apart from each other and a pair of second structures 200b spaced part from each other are connected to each other to form a closed structure. Points where the first and second structures 200a and 200b meat each other may be located on the source and drain electrodes 140 and 150.
Unlike this, according to a modified embodiment, the dam structure 200 may include both of a pair of first structures 200a spaced apart from each other and a pair of second structures 200b spaced part from each other, and have an open structure in which the first and second structures 200a and 200b do not meet each other. Even in this case, the length X2 of the first structures 200a may be greater than the distance X1 between the source and drain electrodes 140 and 150, and the width Y1 of the second structures 200b may be less than the width Y2 of the source and drain electrodes 140 and 150.
In a biosensing device according to a modified embodiment of the present invention, the dam structure 200 may include only the first structures 200a. For example, only a pair of first structures 200a spaced apart from each other may be provided without providing the second structures 200b, and an end of each of the first structures 200a may be provided on the source electrode 140 whereas the other end thereof may be provided on the drain electrode 150. Even in this case, the length X2 of the first structures 200a may be greater than the distance X1 between the source and drain electrodes 140 and 150.
In a biosensing device according to another modified embodiment of the present invention, the dam structure 200 may include only the second structures 200b. For example, only a pair of second structures 200b spaced apart from each other may be provided without providing the first structures 200a, and one of the second structures 200b may be provided on the source electrode 140 whereas the other of the second structures 200b may be provided on the drain electrode 150. Even in this case, the width Y1 of the second structures 200b may be less than the width Y2 of the source and drain electrodes 140 and 150.
The above-described bio-sensing device according to an embodiment of the present invention may be used as a test device to diagnose a disease and may be utilized as a sensing device that uses immune reaction between an antigen and an antibody based on types of a sensing membrane and a receptor. In this case, since an electrical measurement result is used, an analysis process may not be complicated, a device for analysis may be low-priced, and a short analysis time may be taken.
The number of unit cells 10 per substrate 100 is 8×12, i.e., 96 in total, in
Referring to
Although not shown in
Referring to
The size, position, and shape of the sensing membrane 190 may be determined based on the size, position, and shape of the dam structure 200. Based on the above description of the dam structure 200, a side of the sensing membrane 190 may be provided on the source electrode 140 whereas the other side of the sensing membrane 190 may be provided on the drain electrode 150, and a length of the sensing membrane 190 may be greater than a distance between the source and drain electrodes 140 and 150 whereas a width of the sensing membrane 190 may be less than a width of the source and drain electrodes 140 and 150.
Referring to
While the precursor solution 190a is being dried and solidified, a solute of the precursor solution 190a may be mostly concentrated in edges of the region of the precursor solution 190a illustrated in
Referring to
Referring to
Therefore, when the position, size, and shape of the dam structure 200 are controlled as described above in relation to
Referring to
As described above, a solidification density of a sensing membrane 190 may be higher in a region adjacent to the dam structure 200 compared to a region far apart from the dam structure 200. When three or more separate dam structures 200 are formed by the first structures 200a provided in the direction proceeding from the source electrode 140 toward the drain electrode 150, compared to the case of
In the biosensing device illustrated in
For example, when the dam structure 200 includes four first structures 200a extending between the source and drain electrodes 140 and 150, the sensing membrane 190 formed by solidifying the precursor solution 190a may include a first sensing membrane 190-1, a second sensing membrane 190-2, and a third sensing membrane 190-3 separately formed between the four first structures 200a. In this case, since a solidification density of the second sensing membrane 190-2 is concentrated near the first structures 200a, ultimately, not only channels extending between the upper and lower parts of the source and drain electrodes 140 and 150 but also channels extending between the central parts of the source and drain electrodes 140 and 150 may be effectively formed and thus electrical conductivity may be increased.
While the present invention has been particularly shown and described with reference to embodiments thereof, it will be understood by one of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2017-0084894 | Jul 2017 | KR | national |
