An integrated thermal biosensor array for multianalyte determination demonstrated with glucose, urea and penicillin

An integrated thermal biosensor array was designed and fabricated for the simultaneous determination of glucose, urea and penicillin. The sensor contains six thin-film thermistors which were fabricated on quartz chip by micromachining and semiconductor technology. This sensor allows the determination of three different analytes nearly simultaneously by serially partitioning a single microchannel into three distinct detection regions. Each of the regions contained one immobilized enzyme matrix and a pair of thermistors for differential measurement of temperature changes in association with the enzyme reactions. Using this device, glucose, urea and penicillin-G at different concentrations were determined in the mixed samples. Linear ranges of 1 to at least 25 mM urea and penicillin, and up to 20 mM glucose were obtained using a sample volume of 20 mu L.