An amperometric silicon-based biosensor for D-lactate

A miniaturised biosensor for D-lactate has been fabricated on silicon wafer . Microsystems technologies led to enhanced efficiency in terms of sample s ize and reagent consumption while equally allowing mass production. The bio sensor is based on the association of an enzymatic solution including diaph orase and D-lactate dehydrogenase confined in the microstructure by a membr ane and two weal;ly polarised gold microelectrodes. Various electrochemical pretreatments of the gold surface are performed to increase the device's s ensitivity. Depending on the geometry involved, the proposed biosensor feat ures a response time ranging from 2 to 5 min, a sensitivity of 2 or 8 mu A mM(-1) cm(-2) and a linearity range from 5 X 10(-3) to 1.5 mmol l(-1). Its lifetime is 3 weeks with 10 assays/day. (C) 2000 Elsevier Science S.A. All rights reserved.