US 12,111,278 B2
Portable impedance based chemical sensor
Adam Hauser, Tuscaloosa, AL (US); Jennifer Rose Soliz, Ellicott City, MD (US); and Smriti Ranjit, Tuscaloosa, AL (US)
Assigned to The Board of Trustees of the University of Alabama, Tuscaloosa, AL (US); and The U.S. Army, Edgewood Chemical and Biological Center, Aberdeen Proving Ground, MD (US)
Filed by The Board of Trustees of the University of Alabama, Tuscaloosa, AL (US); and The U.S. Army, Edgewood Chemical and Biological Center, Aberdeen Proving Ground, MD (US)
Filed on Apr. 30, 2019, as Appl. No. 16/398,825.
Claims priority of provisional application 62/799,660, filed on Jan. 31, 2019.
Prior Publication US 2020/0249190 A1, Aug. 6, 2020
Int. Cl. G01N 27/22 (2006.01); G01N 27/02 (2006.01); G01N 29/22 (2006.01)
CPC G01N 27/221 (2013.01) [G01N 27/026 (2013.01); G01N 29/226 (2013.01); G01N 2027/222 (2013.01)] 17 Claims
OG exemplary drawing
 
1. An apparatus for sensing a target analyte, the apparatus comprising:
a sensing material comprising a baseline composition and a dopant that reacts with the target analyte, wherein the dopant corresponds to a selectivity of the sensing material for the target analyte,
wherein the sensing material comprises a metal hydroxide or a mixed metal hydroxide,
wherein the dopant is selected from the group consisting of CoCl2, CoS2, Co(NO3)2, Co(NH3)2, Co(acetate)2, CuS2, CuCl2, Cu(NO3)2, Cu(NH3)2, Cu(acetate)2, Ni(NO3)2, Ni(NH3)2, NiS2, NiCl2, FeCl3, FeS3, Fe(NO3)3, Fe(NH3)3, Ln(NO3)x (Ln=lanthanides), Ln(acetate)x, and combinations thereof;
wherein the sensing material is in electrical communication with an energy source that directs an input of either an AC voltage or an AC current across the sensing material at a first frequency, at least a portion of the sensing material positioned in an exposed state relative to an environment;
wherein the sensing material is configured to be placed within the environment such that the exposed state comprises a concentration of the target analyte proximate the sensing material, and
wherein the sensing material comprises structural features allowing a target analyte to change a composition of the sensing material by reacting with the dopant;
an impedance detection device connected to a sensing circuit and receiving an output from the sensing material, the output exhibiting a respective impedance value of the sensing material corresponding to the input for the first frequency; and
wherein the respective impedance value is dependent upon the dopant, the concentration of the target analyte in the environment and the first frequency.