Acetone sensor and associated methods

1 . A sensor for detecting acetone, comprising:

a substrate;

a pair of interdigitated electrodes disposed on the substrate; and

a sensing film disposed on the pair of interdigitated electrodes, wherein the sensing film comprises a molecularly imprinted polymer deposited on top of an electrically conductive polymer film, and the sensing film exhibits electrical conductivity that is dependent on concentration of acetone vapor to which said sensing film is exposed.

2 . The sensor of claim 1 , wherein the electrical conductivity increases with increasing acetone concentration.

3 . The sensor of claim 1 , wherein the molecularly imprinted polymer film has a thickness between 100 nanometers and 1 micrometer, or wherein the sensing film has a thickness between 100 nanometers and 1 micrometer.

4 . The sensor of claim 1 , wherein the molecular imprinted polymer comprises a co-polymer comprising polymethacrylic acid and polymethacrylate.

5 . The sensor of claim 4 , wherein the polymethacrylic acid and the polymethacrylate are present in the co-polymer at a concentration sufficient to achieve a rate of electrical conductivity change with respect to the concentration of acetone between 10 ppb and 200 ppm.

6 . The sensor of claim 5 , wherein the concentration of the polymethacrylic acid is between 1% and 15% by weight of the co-polymer.

7 . The sensor of claim 1 , wherein the electrically conductive polymer film comprises polyaniline or polypyrrole.

8 . The sensor of claim 1 , wherein the substrate comprises glass, silicon, or a printed circuit board.

9 . An acetone sensing system, comprising:

a plurality of sensors of claim 1 .

10 . The acetone sensing system of claim 9 , further comprising a control unit, wherein for each sensor of the plurality of sensors the control unit:

induces an electric current to flow through each sensor; and

generates an acetone concentration measurement based on the electrical conductivity.

11 . The acetone sensing system of claim 9 , wherein each sensor of the plurality of sensors comprises a sensor rate corresponding to a detection range of acetone concentrations comprising two or more of 10 ppb, 100 ppb, 1 ppm, 10 ppm, 25 ppm, 50 ppm, 100 ppm, and 250 ppm.

12 . A method for detecting acetone comprising:

providing a plurality of sensors of claim 1 ,

and

for each sensor of the plurality of sensors, generating a signal when said sensor is exposed to a sample of acetone having gas density greater than or equal to an acetone detection threshold of said sensor;

wherein each sensor of the plurality of sensors has an acetone detection limit that spans a detection range.

13 . The method of claim 12 , wherein the acetone detection threshold is selected from the group consisting of 10 ppb, 100 ppb, 1 ppm, 10 ppm, 25 ppm, 50 ppm, 100 ppm, and 250 ppm acetone.

14 . A method for forming the sensor of claim 1 , comprising:

depositing a pair of electrodes on a substrate;

dissolving a co-polymer and suspending conductive nanoparticles in an organic solvent to form a sensing solution; and

coating the pair of electrodes with the sensing solution to form a conductive sensing film on the pair of electrodes, thereby forming the sensor of claim 1 .

15 . The method of claim 14 , wherein the pair of electrodes is a pair of interdigitated electrodes.

16 . The method of claim 14 , wherein the conductive nanoparticles comprise one or more of carbon, gold, and silver.