Development of microbiosensors

Abstract

AbstractSemiconductor fabrication technology was used for development of ion sensitive field effect transistor (ISFET) and micro‐electrodes which have been utilized as transducers of enzyme‐based microbiosensors. A urea sensor consisted of two ISFETs; one ISFET is urease‐coated ISFET and the other ISFET is reference ISFET. A linear relationship was obtained between the initial rate of voltage change and the logarithm of urea concentration over the range 1.3 to 16.7 mM. ATP and hypoxanthine sensors were also developed utilizing ISFET as a transducer. Furthermore, microelectrodes such as hydrogen peroxide and oxygen sensors were prepared by the silicone fabrication technology. A glucose sensor consisted of a hydrogen peroxide electrode and immobilized glucose oxidase membrane. A linear relationship was observed between the current increase and the concentration of glucose (1–100 mg dl−1). A microoxygen electrode was constructed from Au electrodes, polymer matrix containing alkaline electrolyte and a photocross‐linkable polymer membrane. This electrode was used as a transducer in microglucose sensor. A microglutamic acid sensor is also described.