| abstract |
A sensor system that detects a current representative of a compound in a liquid mixture features a multi or three electrode strip adapted for releasable attachment to signal readout circuitry. The strip comprises an elongated support which is preferably flat adapted for releasable attachment to the readout circuitry; a first conductor and a second and a third conductor each extend along the support and comprise means for connection to the circuitry. The circuit is formed with single-walled or multi walled nanotubes conductive traces and may be formed from multiple layers or dispersions containing, carbon nanotubes, carbon nanotubes/antimony tin oxide, carbon nanotubes/platinum, or carbon nanotubes/silver or carbon nanotubes/silver-cloride. An active electrode formed from a separate conductive carbon nanotubes layer or suitable dispersion, positioned to contact the liquid mixture and the first conductor, comprises a deposit of an enzyme capable of catalyzing a reaction involving the compound and preferably an electron mediator, capable of transferring electrons between the enzyme-catalyzed reaction and the first conductor. A reference electrode also formed from a conductive carbon nanotube layer or suitable dispersion is positioned to contact the mixture and the second conductor. The system includes circuitry adapted to provide an electrical signal representative of the current which is formed from printing conductive inks made with nano size particles such as conductive carbon or carbon/platinum or carbon/silver, or carbon nanotubes/antimony tin oxide to form a conductive carbon nanotube layers. The multiple-electrode strip is manufactured, by then applying the enzyme and preferably the mediator onto the electrode. Alternatively the electrode can have a carbon nanotubes/antimony tin oxide, carbon nanotubes/platinum, or carbon nanotubes/silver or carbon nanotubes/silver-cloride surface and or a conductive carbon or silver ink surface connecting leg. The carbon nanotube solution is first coated and patterned into electro shapes and the conductive carbon nanotubes, carbon or silver ink can be attached by printing the ink to interface with the carbon nanotube electro surface. A platinum electrode test strip is also disclosed that is formed from either nano platinum distributed in the carbon nanotube layer or by application or incorporation of platinum to the carbon nanotube conductive ink. |