# US 12,181,469 B2 · Chemical sensor, method for detecting target substance, and apparatus for detecting the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,469 B2 - Document ID: US12181469B2 - Status: Granted - Kind: B2 - Application number: 17/470,880 - Filed: 2021-09-09 - Published: 2022-09-22 - Granted: 2024-12-31 - Earliest claimed: 2021-03-18 - Assignees: Kabushiki Kaisha Toshiba - Applicants: Kabushiki Kaisha Toshiba - Inventors: Yoshiaki Sugizaki - Web page: https://patentgrep.com/patent/US12181469B2 ## CPC - G01N 33/54373: {involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings} - C07K 14/705: Receptors; Cell surface antigens; Cell surface determinants {(tumour specific antigens C07K14/4748)} - G01N 33/54306: {Solid-phase reaction mechanisms} - G01N 33/566: using specific carrier or receptor proteins as ligand binding reagents {where possible specific carrier or receptor proteins are classified with their target compounds} - G01N 33/74: involving hormones {or other non-cytokine intercellular protein regulatory factors such as growth factors, including receptors to hormones and growth factors} - G01N 2333/726: G protein coupled receptor, e.g. TSHR-thyrotropin-receptor, LH/hCG receptor, FSH - 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) - C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00) ## Abstract According to one embodiment, a chemical sensor for detecting a target substance in a specimen, the chemical sensor including a sensitive film, a first extracellular region peptide of a transmembrane receptor immobilized on the sensitive film, a liquid phase disposed on the sensitive film, and a second extracellular region peptide of the transmembrane receptor contained within the liquid phase. ## Claims ### Claim 1 A chemical sensor for detecting a target substance in a specimen, the chemical sensor comprising: a sensitive film; a first extracellular region peptide of a transmembrane receptor immobilized on the sensitive film; a liquid phase disposed on the sensitive film; and a second extracellular region peptide of the transmembrane receptor contained within the liquid phase, wherein the extracellular region is an extracellular loop, and the first extracellular region peptide and the second extracellular region peptide contain at least a part of amino acid sequence of the extracellular loop, and are circularized. ### Claim 2 (depends on 1) The chemical sensor according to claim 1, further comprising: a first electrode connected to one end of the sensitive film; and a second electrode connected to the other end of the sensitive film, wherein the sensitive film is made of graphene. ### Claim 3 (depends on 1) The chemical sensor according to claim 1, wherein the transmembrane receptor includes a plurality of extracellular regions, and the first extracellular region peptide and the second extracellular region peptide each contain at least a part of amino acid sequence of the mutually different extracellular regions of the transmembrane receptor. ### Claim 4 (depends on 3) The chemical sensor according to claim 3, wherein the part of the amino acid sequence is less than 40 mer. ### Claim 5 (depends on 1) The chemical sensor according to claim 1, further comprising: a plurality of the sensitive films, wherein the liquid phase is isolated for each of the plurality of sensitive films, and the first extracellular region peptides and the second extracellular region peptides are derived from transmembrane receptors different from each other among the plurality of sensitive films. ### Claim 6 (depends on 1) A detecting apparatus comprising: the chemical sensor according to claim 1; a detection unit that converts a change in physical properties of the sensitive film into a change in an electrical signal; a specimen introduction unit that takes the specimen into the liquid phase of the chemical sensor; and a processor that determines presence or absence or an amount of a target substance in the specimen by processing information of the electrical signal obtained from the detection unit.