Materials and sensors for detecting gaseous agents

1. A sensor configured to detect a gaseous agent comprising:

a transducer, wherein the transducer comprises an electrical resonant circuit that forms an antenna; and

a sensing material disposed at least on the portion of the transducer, wherein the sensing material comprises a tunable polymer additive configured to enable the sensing material to achieve an improved sensing performance, and wherein the sensing material is configured to simultaneously exhibit a capacitance response and a resistance response when exposed to a gaseous agent.

2. The sensor of claim 1 , wherein the gaseous agent is a sterilization agent, a fumigation agent, or a decontamination agent.

3. The sensor of claim 1 , wherein the sensing material has a reversible response when exposed to the gaseous agent.

4. The sensor of claim 1 , wherein the sensing material is configured to measure a concentration of the gaseous agent as a dosimeter.

5. The sensor of claim 1 , wherein the sensing material comprises metal nanoparticles coated at least in part with an organic layer.

6. The sensor of claim 1 , wherein the sensing material comprises a semiconducting metal oxide and a noble metal catalyst deposited on the semiconducting metal oxide.

7. The sensor of claim 6 , wherein the noble metal catalyst is any one of the following: platinum, palladium, gold, silver, aluminum, copper, iron, nickel, ruthenium, or any combination thereof, and wherein the semiconducting metal oxide is any one of the following: In 2 O 3 , ZnO, WO 3 , SnO 2 , TiO 2 , Fe 2 O 3 , Ga 2 O 3 and Sb 2 O 3 or any other semiconducting metal oxide, or a combination of one or more metals including In 2 O 3 with SnO 2 , In 2 O 3 with ZnO, SnO 2 with ZnO, or any other combination of metals.

8. The sensor of claim 6 , wherein the noble metal catalyst is deposited on the semiconducting metal oxide using wetness impregnation or in-situ synthesis.

9. The sensor of claim 6 , wherein the weight percentage of noble metal catalyst to semiconducting metal oxide is in the range of 0.01% to 1%.

10. The sensor of claim 1 , wherein the sensor is configured to operate at an ambient temperature.

11. The sensor of claim 10 , wherein the ambient temperature is between −40 degrees Centigrade to 1000 degrees Centigrade.

12. The sensor of claim 1 , wherein the transducer is a passive RFID platform transducer, an inductor-capacitor-resistor (LCR) resonator, a thickness shear mode resonator, an interdigital electrode structure, or an electrode structure.

13. The sensor of claim 1 , wherein the sensing material is disposed on a complementary sensing region of the sensor.

14. A sensor configured to detect a gaseous agent, the sensor comprising:

a transducer, wherein the transducer comprises an antenna;

a sensing material disposed on the transducer, wherein the sensing material comprises a semiconducting metal oxide, a noble metal catalyst deposited on the semiconducting metal oxide, and a tunable polymer additive configured to enable the sensing material to achieve an improved sensing performance; and

wherein the antenna is configured to emit an electric field to probe a response of the sensing material when exposed to a gaseous agent.

15. The sensor of claim 14 , wherein the semiconducting metal oxide is a semiconducting mixed metal oxide.

16. The sensor of claim 14 , wherein the sensing material comprises between 1% and 80% of the tunable polymer additive.

17. The sensor of claim 14 , wherein the response of the sensing material is both a change in a capacitance and a change in a resistance.

18. The sensor of claim 14 , wherein the sensing material is disposed on a complementary sensing region of the sensor.

19. A method for preparing a sensor configured to detect a gaseous agent comprising:

assembling a transducer by disposing an antenna on a substrate;

doping a noble metal catalyst to a semiconducting metal oxide to form a metal oxide powder;

mixing the metal oxide powder with an aqueous solution of a polymer matrix to form a stable metal oxide suspension;

depositing the metal oxide suspension on the transducer; and

drying the metal oxide suspension to form a sensing material, wherein the polymer matrix is configured to enable the sensing material to achieve an improved sensing performance.

20. The method of claim 19 , wherein the noble metal catalyst is any one of the following: platinum, palladium, gold, silver, aluminum, copper, iron, nickel, ruthenium, or any combination thereof.

21. The method of claim 19 , wherein the semiconducting metal oxide is any one of the following: In 2 O 3 , ZnO, WO 3 , SnO 2 , TiO 2 , Fe 2 O 3 , Ga 2 O 3 and Sb 2 O 3 or any other semiconducting metal oxide, or a combination of one or more metals including In 2 O 3 with SnO 2 , In 2 O 3 with ZnO, SnO 2 with ZnO, or any other combination of metals.

22. The method of claim 19 , wherein the polymer matrix is formed by dissolving a polymer additive in water, ethanol, isopropanol, hexane, toluene, 1-Methyl-2-Pyrrolidinone, or any combination thereof.

23. The method of claim 19 , wherein the polymer matrix is any of the following: polyvinlyldene fluoride (PVDF), polyvinyl alcohol (PVO), polyacrylic acid (PAA), chloro metal acid, or any combination thereof.

24. The method of claim 18 , wherein disposing the antenna on the transducer is performed using printing.

25. A method for detecting a concentration of a gaseous agent comprising:

exposing a sensing material to a gaseous agent, wherein the sensing material comprises a first component, a second component, and a tunable polymer additive, and wherein the first component, the second component, and the tunable polymer additive are deposited on a surface of a sensing coil, wherein the tunable polymer additive is configured to enable the sensing material to achieve an improved sensing performance;

oxidizing or reducing the first component and/or the second component;

measuring a capacitance response and a resistance response of the sensing material over a frequency range; and

conducting analysis on the capacitance response and the resistance response of the sensing material to detect a concentration of the gaseous agent.

26. The method of claim 25 , wherein the sensing material comprises metal nanoparticles coated at least in part with an organic layer.

27. The method of claim 25 , wherein the analysis is univariate or multivariate.

28. The method of claim 25 , wherein the first component is a semiconducting metal oxide and the second component is a noble metal catalyst, and wherein the noble metal catalyst is deposited on the surface of the semiconducting metal oxide.

29. The method of claim 25 , wherein the analysis facilitates for self-correction against fluctuations in ambient temperature.

30. The method of claim 25 , wherein the sensing material has a reversible response to the gaseous agent.

31. The sensor of claim 1 , wherein a weight percent of the tunable polymer additive in the sensing material is between 60% and 80%.

32. The sensor of claim 1 , wherein a weight percent of the tunable polymer additive in the sensing material is approximately 76%.

33. The sensor of claim 1 , wherein the improved sensing performance is to simultaneously exhibit the capacitance response and the resistance response when exposed to a gaseous agent at a concentration of about 30 parts per million (ppm) and 300 ppm without exhibiting a response saturation at 300 ppm.

34. The sensor of claim 14 , wherein a weight percent of the tunable polymer additive in the sensing material is between 60% and 80%.

35. The sensor of claim 14 , wherein a weight percent of the tunable polymer additive in the sensing material is approximately 76%.

36. The sensor of claim 14 , wherein the improved sensing performance is to exhibit a response when exposed to a gaseous agent at a concentration of about 30 parts per million (ppm) and 300 ppm without exhibiting a response saturation at 300 ppm.