# US 12,601,688 B2 · Silver coordination polymers for measuring arsenic levels in water > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,601,688 B2 - Document ID: US12601688B2 - Status: Granted - Kind: B2 - Application number: 18/008,496 - Filed: 2021-06-07 - Published: 2023-07-06 - Granted: 2026-04-14 - Earliest claimed: 2020-06-06 - Assignees: The Trustees of Columbia University in the City of New York; Barnard College - Applicants: The Trustees of Columbia University In the City of New York; Barnard College - Inventors: Michael G. Campbell; Benjamin C. Bostick; Natasha Reich - Web page: https://patentgrep.com/patent/US12601688B2 ## CPC - C02F 1/288: {using composite sorbents, e.g. coated, impregnated, multi-layered} - G01N 21/78: producing a change of colour - G01N 31/22: using chemical indicators (G01N31/02 takes precedence) - G01N 33/182: {Specific anions in water} - C02F 2101/103: {Arsenic compounds} - C02F 2103/06: Contaminated groundwater or leachate - G01N 33/1813: {Specific cations in water, e.g. heavy metals} - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - 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) ## Abstract Measurement devices can be used for identifying concentration of arsenic species in water samples. The measurement devices can take the form of test strips including a substrate with at least one testing region that includes an amount of a testing medium. The silver reagent includes a polymer framework and a silver component that is stabilized by the framework, yet remains reactive enough to function as a colorimetric sensor for arsenic, e.g., ((Ag(H2btc))(Ag2(Hbtc)))n. The initially substantially colorless testing medium exhibits a color change response when exposed to arsenic species, e.g., arsine, generated from samples including as little as 5 ppb arsenic, with an increasingly dark color as the concentration of arsenic is increased. Test strips fabricated with the silver coordination polymer display robust stability towards both light and water, allowing for an alternative to mercury-based field test kits in real-world field tests under direct sunlight and high humidity conditions. ## Claims ### Claim 1 A method of detecting a concentration of arsenic in a medium, comprising: obtaining a sample of the medium; administering an amount of the sample to a substrate that includes an amount of a silver reagent; and measuring a characteristic change of the silver reagent, wherein the silver reagent includes a polymeric framework including elemental silver, at least one silver salt, at least one silver compound, or combinations thereof. ### Claim 2 (depends on 1) The method according to claim 1, wherein the characteristic change is a colorimetric change. ### Claim 3 (depends on 1) The method according to claim 1, wherein the amount of silver reagent is at least sufficient to generate an observable colorimetric change in the presence of 5 ppb arsenic species. ### Claim 4 (depends on 1) The method according to claim 1, wherein the polymeric framework is water insoluble. ### Claim 5 (depends on 1) The method according to claim 1, wherein the silver reagent includes: ((Ag(H2btc))(Ag2(Hbtc)))n. ### Claim 6 (depends on 1) The method according to claim 1, wherein the silver reagent is formed by reacting a trimesic acid with at least a first silver compound. ### Claim 7 (depends on 6) The method according to claim 6, wherein the at least a first silver compound includes silver nitrate. ### Claim 8 (depends on 1) The method according to claim 1, wherein the medium includes surface water, groundwater, industrial effluent, or combinations thereof. ### Claim 9 A measurement device for identifying a concentration of arsenic species in a medium, the device comprising: a substrate; and a testing region positioned on at least a portion of the substrate, the testing region including an amount of a silver reagent, wherein the silver reagent includes a polymeric framework including elemental silver, at least one silver salt, at least one silver compound, or combinations thereof. ### Claim 10 (depends on 9) The device according to claim 9, wherein the amount of silver reagent is at least sufficient to generate an observable colorimetric change in the presence of 5 ppb arsenic species. ### Claim 11 (depends on 9) The device according to claim 9, wherein the silver reagent includes: ((Ag(H2btc))(Ag2(Hbtc)))n. ### Claim 12 (depends on 9) The device according to claim 9, wherein the silver reagent is formed by reacting a trimesic acid with a silver nitrate. ### Claim 13 A method of making a measurement device, the method comprising: providing a substrate; and administering an amount of a silver reagent to at least a portion of the substrate to form a testing region positioned thereon, wherein the silver reagent includes a polymeric framework including elemental silver, at least one silver salt, at least one silver compound, or combinations thereof. ### Claim 14 (depends on 13) The method according to claim 13, wherein the amount of silver reagent in the testing region is at least sufficient to generate an observable colorimetric change in the presence of 5 ppb arsenic species. ### Claim 15 (depends on 13) The method according to claim 13, wherein the polymeric framework is water insoluble. ### Claim 16 (depends on 13) The method according to claim 13, wherein administering an amount of a silver reagent to at least a portion of the substrate to form a testing region positioned includes: reacting a trimesic acid with at least a first silver compound to form the silver reagent. ### Claim 17 (depends on 16) The method according to claim 16, wherein the at least a first silver compound includes silver nitrate. ### Claim 18 (depends on 17) The method according to claim 17, wherein the silver reagent includes: ((Ag(H2btc))(Ag2(Hbtc)))n.