# US 2021/0239646 A1 · Rgo-based biosensor, manufacturing method of same, and detection method for biomaterial > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0239646 A1 - Document ID: US20210239646A1 - Status: Published application - Kind: A1 - Application number: 17/059,344 - Filed: 2019-05-29 - Published: 2021-08-05 - Earliest claimed: 2018-05-31 - Assignees: Xyz Platform Inc. - Applicants: Xyz Platform Inc. - Inventors: Kyo Seon HWANG; Myung Sic CHAE; Dong Sung PARK; Yong Kyoung YOO; Jae Hyun KIM - Web page: https://patentgrep.com/patent/US20210239646A1 ## CPC - G01N 27/4145: {specially adapted for biomolecules, e.g. gate electrode with immobilised receptors} - G01N 33/5438: {Electrodes} - H10P 14/6342: {Liquid deposition, e.g. spin-coating, sol-gel techniques or spray coating} - H10P 76/2041: {Photolithographic processes} - G01N 2333/4709: Amyloid plaque core protein - G01N 2333/918: Carboxylic ester hydrolases (3.1.1) - G01N 2800/2821: Alzheimer - H10D 62/882: {Graphene} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract The RGO (Reduced Graphene Oxide)-based bio sensor according to the present invention comprises: a source electrode and a drain electrode formed on a substrate; an RGO channel formed between the source electrode and the drain electrode; a PDMS (polydimethylsiloxane) chip supplying a reaction solution to the RGO channel; a passivation layer for sealing in order to prevent the reaction solution supplied through the PDMS chip from touching the source electrode and the drain electrode; and a gate electrode electrically connected to the reaction solution contacted to the RGO by being supplied through the PDMS chip. At this time, the passivation layer is formed with a SU-8 photoresistor, and the gate electrode is directly contacted to the reaction solution to thereby realize a liquid phase driving. The passivation layer is formed with SU-8 to allow supply of reaction solution through PDMS chip to be conveniently and stably realized. The operation is made possible at a gate voltage of −1.0V˜1.0V due to liquid driving of gate electrode, thereby enabling to realize FET type bio sensor having a high sensitivity. ## Claims ### Claim 1 An RGO (Reduced Graphene Oxide)-based bio sensor for detecting bio material within a liquid phase, comprising: a substrate; a source electrode and a drain electrode formed on the substrate; an RGO channel formed between the source electrode and the drain electrode; a PDMS (polydimethylsiloxane) chip supplying a reaction solution to the RGO channel; a passivation layer for sealing in order to prevent the reaction solution supplied through the PDMS chip from touching the source electrode and the drain electrode; and a gate electrode electrically connected to the reaction solution contacted to the RGO by being supplied through the PDMS chip. ### Claim 2 (depends on 1) The RGO-based bio sensor of claim 1, wherein the passivation layer is formed with a SU-8 photoresistor. ### Claim 3 (depends on 1) The RGO-based bio sensor of claim 1, wherein the gate electrode is directly contacted to the reaction solution. ### Claim 4 A method for manufacturing an RGO-based bio sensor, the method comprising: forming a source electrode and a drain electrode on a substrate (first step); forming an RGO layer on the substrate formed with the source electrode and the drain electrode (second step); forming a first protective layer on the RGO layer (third step); forming an RGO channel between the source electrode and the drain electrode by performing a patterning process (fourth step); forming a passivation layer encompassing a surrounding of the RGO channel including the source electrode and the drain electrode (fifth step); and removing the first protective layer (sixth step). ### Claim 5 (depends on 4) The method of claim 4, wherein each of the source electrode and the drain electrode is formed with Cr/Au with a thickness of 20 nm/100 nm, and the first protective layer is formed with Al2O3 with a thickness of 50 nm. ### Claim 6 (depends on 5) The method of claim 5, wherein the first protective layer in the sixth step is removed under an environment of wet etchant being heated at 180° C. ### Claim 7 (depends on 4) The method of claim 4, wherein the substrate is an Si/SiO2 substrate, and the second step includes: fixing a 5% 3-aminopropyltriethoxysilane (APTES) onto the substrate; depositing on the substrate, through a spin coating method, a diluted solution in which a GO is diluted in distilled water by 3 mg/mL concentration; and generating a reduction reaction by exposing the deposited GO film to a hydroiodic acid (HI) vapor of 80° C. for a predetermined time. ### Claim 8 (depends on 7) The method of claim 7, wherein the spin coating is performed for 30 seconds at 4,000 rpm, and the time of exposing the GO film to hydroiodic acid (HI) vapor of 80° C. is 3 hours. ### Claim 9 (depends on 4) The method of claim 4, wherein the fourth step includes patterning the RGO channel on the first protective layer using photoresistor and processing by dry etching method. ### Claim 10 (depends on 4) The method of claim 4, wherein the passivation layer is formed with a SU-8 photoresistor. ### Claim 11 (depends on 4) The method of claim 4, comprising: attaching, on the passivation layer, the PDMS chip for supplying reaction solution to the RGO channel. ### Claim 12 (depends on 1) A method for detecting a bio material using an RGO-based bio sensor, the method comprising: fixing a bio material onto a RGO channel of RGO-based bio sensor according to claim 1; supplying a reaction solution to the fixed bio material; seeking a Dirac point by measuring a current flowing between a drain electrode and a source electrode and a voltage; and determining one or more of whether to detect a target material included in the reaction solution in response to the Dirac point and concentration, wherein the gate voltage is directly applied to the reaction solution while the reaction solution is contacted to the RGO channel. ### Claim 13 (depends on 12) The method of claim 12, wherein the Dirac point is more than −1V but less than 1V. ### Claim 14 (depends on 12) The method of claim 12, wherein the bio material includes 6E10 antibody or AChE (acetylcholinesterase) useable for diagnosing an Alzheimer's disease. ### Claim 15 (depends on 11) A method for detecting a bio material using an RGO-based bio sensor, the method comprising: fixing a bio material to an RGO channel of bio sensor manufactured by the RGO-based bio sensor manufacturing method of claim 11; suppling a reaction solution to the fixed bio material; seeking a dirac point by measuring a current flowing between a drain electrode and a source electrode and a gate voltage; and determining one or more of whether to detect a target material included in the reaction solution in response to the dirac point and concentration, wherein the gate voltage is directly applied to the reaction solution while the reaction solution is contacted to the RGO channel. ### Claim 16 (depends on 5) The method of claim 5, comprising: attaching, on the passivation layer, the PDMS chip for supplying reaction solution to the RGO channel. ### Claim 17 (depends on 7) The method of claim 7, comprising: attaching, on the passivation layer, the PDMS chip for supplying reaction solution to the RGO channel. ### Claim 18 (depends on 9) The method of claim 9, comprising: attaching, on the passivation layer, the PDMS chip for supplying reaction solution to the RGO channel. ### Claim 19 (depends on 2) A method for detecting a bio material using an RGO-based bio sensor, the method comprising: fixing a bio material onto a RGO channel of RGO-based bio sensor according to claim 2; supplying a reaction solution to the fixed bio material; seeking a Dirac point by measuring a current flowing between a drain electrode and a source electrode and a voltage; and determining one or more of whether to detect a target material included in the reaction solution in response to the Dirac point and concentration, wherein the gate voltage is directly applied to the reaction solution while the reaction solution is contacted to the RGO channel. ### Claim 20 (depends on 3) A method for detecting a bio material using an RGO-based bio sensor, the method comprising: fixing a bio material onto a RGO channel of RGO-based bio sensor according to claim 3; supplying a reaction solution to the fixed bio material; seeking a Dirac point by measuring a current flowing between a drain electrode and a source electrode and a voltage; and determining one or more of whether to detect a target material included in the reaction solution in response to the Dirac point and concentration, wherein the gate voltage is directly applied to the reaction solution while the reaction solution is contacted to the RGO channel.