Patent ID: 8309028

Claim:
A sensor for measuring the presence or amount of analyte in an electrolyte solution of predetermined permittivity ∈; said sensor comprising: (i) two electrically conducting electrodes on an electrically insulating substrate, and separated by a distance L, where L is between 10 nm and 10 μm; (ii) a chemiresistor film, wherein the impedance of the chemiresistor film changes in the presence of an analyte; wherein the chemiresistor film is in contact with the electrodes; wherein the sensor comprises a voltage means configured to provide a low frequency f<f 0 =100 Hz signal or DC voltage across the electrodes; wherein the apparent area A of a double layer capacitor formed by the electrodes and the chemiresistor film in the electrolyte solution is less than half of A 0 , where A 0 = d 2 ⁢ π ⁢ ⁢ f 0 ⁢ ɛɛ 0 ⁢ R and wherein ∈ 0 and d are predetermined and R is the resistance of the electrodes and the chemiresistor film in the electrolyte solution.