Methods and devices for determining sensing device usability

1. A method of determining device usability of an analyte sensing device, comprising the steps of:

providing an analyte sensing device comprising a first electrical pad; a second electrical pad; and a humidity-responsive polymer layer contacting at least a portion of said first and said second electrical pads;

applying a potential across said first and said second electrical pads, wherein the first electrical pad is connected to an analyte sensing electrode and the second electrical pad is connected to a reference electrode;

measuring an electrical property associated with said humidity-responsive polymer layer; and

determining whether said measured electrical property associated with said humidity-responsive polymer layer has exceeded a humidity threshold level associated with said analyte sensing device usability,

wherein said humidity-responsive polymer layer is selected from the group consisting of a crosslinked polyvinylpyrrolidone (PVP), a crosslinked polymer containing nitrogen heterocyclic groups, and combinations thereof.

2. The method of claim 1 , wherein said analyte sensing device is a glucose sensor or a ketone body sensor.

3. The method of claim 1 , wherein said analyte sensing device is a sensor selected from the group consisting of a pH sensor, oxygen sensor, carbon dioxide sensor, hematocrit sensor, lactate sensor, creatinine sensor, sodium sensor, potassium sensor, chloride sensor, calcium sensor, BNP sensor, troponin sensor, CKMB sensor, NGAL sensor, TSH sensor, D-dimer sensor, PSA sensor, PTH sensor, cholesterol sensor, ALT sensor, AST sensor, prothrombin sensor, APTT sensor, ACT sensor, galectin sensor, and combinations thereof.

4. The method of claim 1 , wherein said humidity-responsive polymer layer is substantially rectangular and has sides of length from about 20 μm to about 5 mm.

5. The method of claim 1 , wherein said humidity-responsive polymer layer is applied to said device by a method selected from the group consisting of microdispensing, inkjet printing, and screen printing.

6. The method of claim 1 , wherein said first electrical pad and said second electrical pad are separated by a distance of from about 10 μm to about 4 mm.

7. The method of claim 1 , wherein said first electrical pad and said second electrical pad comprise terminal portions of contact lines.

8. The method of claim 1 , wherein said first electrical pad and said second electrical pad comprise non-terminal portions of contact lines.

9. The method of claim 1 , wherein said electrical property comprises current, resistance, impedance, conductivity, or combinations thereof.

10. The method of claim 1 , wherein said potential comprises a sigmoidal potential cycle, a fixed applied potential, a sequence of fixed applied potential steps, or a combination thereof.

11. The method of claim 1 , further comprising inserting said analyte sensing device into an analyzer configured to determine whether said measured electrical property associated with said humidity-responsive polymer layer has exceeded said humidity threshold level associated with said device usability.

12. A method of determining device usability of an analyte sensing device, comprising the steps of:

providing an analyte sensing device comprising a first electrical pad; a second electrical pad; and a humidity-responsive polymer layer contacting at least a portion of said first and said second electrical pads;

applying a potential across said first and said second electrical pads, wherein the first electrical pad is connected to an analyte sensing electrode and the second electrical pad is connected to a reference electrode;

measuring an electrical property associated with said humidity-responsive polymer layer; and

determining whether said measured electrical property associated with said humidity-responsive polymer layer has exceeded a humidity threshold level associated with said analyte sensing device usability,

wherein said humidity-responsive polymer layer is substantially circular and has a diameter of from about 20 μm to about 5 mm.

13. A method of determining device usability of an analyte sensing device, comprising the steps of:

providing an analyte sensing device comprising a first electrical pad; a second electrical pad; and a humidity-responsive polymer layer contacting at least a portion of said first and said second electrical pads;

measuring an initial current value associated with said humidity-responsive polymer layer when said analyte sensing device is manufactured;

applying a potential across said first and said second electrical pads, wherein the first electrical pad is connected to an analyte sensing electrode and the second electrical pad is connected to a reference electrode;

measuring an electrical property associated with said humidity-responsive polymer layer; and

determining whether said measured electrical property associated with said humidity-responsive polymer layer has exceeded a humidity threshold level associated with said analyte sensing device usability,

wherein said humidity threshold level is at least five times higher than said initial current value.

14. A method of determining device usability of an analyte sensing device, comprising the steps of:

providing an analyte sensing device comprising a first electrical pad; a second electrical pad; and a humidity-responsive polymer layer contacting at least a portion of said first and said second electrical pads;

measuring an initial impedance value associated with said humidity-responsive polymer layer when said analyte sensing device is manufactured;

applying a potential across said first and said second electrical pads, wherein the first electrical pad is connected to an analyte sensing electrode and the second electrical pad is connected to a reference electrode;

measuring an electrical property associated with said humidity-responsive polymer layer; and

determining whether said measured electrical property associated with said humidity-responsive polymer layer has exceeded a humidity threshold level associated with said analyte sensing device usability,

wherein said humidity threshold level is at least five times lower than said initial impedance.