SCREEN-PRINTABLE SOL-GEL ENZYME-CONTAINING CARBON INKS

Enzymes usually cannot withstand the high-temperature curing associate d with the thick-film fabrication process and require a separate immob ilization step in connection with the production of single use biosens ors, We report on the development of sol-gel-derived enzyme-containing carbon inks that display compatibility with the screen-printing proce ss, Such coupling of sol-gel and thick-film technologies offers a one- step fabrication of disposable enzyme electrodes, as it obviates the n eed for thermal curing. The enzyme-containing sol-gel carbon ink, prep ared by dispersing the biocatalyst, along with the graphite powder and a binder, within the sol-gel precursors, is cured very rapidly (10 mi n) at low temperature (4 degrees C). The influence of the ink preparat ion conditions is explored, and the sensor performance is evaluated in connection with the incorporation of glucose oxidase or horseradish p eroxidase, The resulting strips are stable for at least 3 months, Such sol-gel-derived carbon inks should serve as hosts for other heat-sens itive biomaterials in connection with the microfabrication of various thick-film biosensors.