THICK-FILM MULTICHANNEL BIOSENSORS FOR SIMULTANEOUS AMPEROMETRIC AND POTENTIOMETRIC MEASUREMENTS

A seven-channel multibiosensor for simultaneous amperometric and poten tiometric operation is described. The transducer is fabricated by scre en-printing techniques in thick-film technology and contains 14 gold e lectrodes, which act as working and counter electrodes, and one silver electrode, which is chlorinated to give an integrated silver/silver c hloride reference electrode. The ion-selective membranes are based on a poly(vinyl chloride)-poly( vinyl acetate) copolymer. Entrapment of e nzymes is achieved by membranes made from organic-solvent-free aqueous polymer dispersions, which can be applied to the sensor electrodes by screen-printing or solder dispenser systems. The sensor is integrated into a flow-injection-analysis (FIA) system and is applied to the ana lysis of blood serum electrolyte (K+, Li+) and metabolite (glucose, ur ea, lactate) status.