Integration of Dual-Mode Glucose Biosensor and pH Sensor via a SnO[sub 2]/Carbon Electrode and Dual-Mode Circuit

In this study, tin oxide thin films are sputtered onto a carbon electrode to develop a /carbon pH sensor. The /carbon pH sensor shows pH sensitivity in the range of pH 2–12, with sensitivity of . Moreover, the electron mediator and enzyme are coimmobilized onto the surface of the base electrode, /carbon pH sensor, to fabricate a /carbon dual-mode glucose biosensor. The operation mode of the dual-mode glucose biosensor, amperometric or potentiometric mode, is determined via the mode selection in the dual-mode circuit. The /carbon dual-mode glucose biosensor demonstrates the detection limit up to . Additionally, to realize the small dimension and low-cost advantages for portable and home-care purposes, a homemade dual-mode circuit is designed for detecting amperometric and potentiometric signals. Hence, the /carbon dual-mode glucose biosensor and pH sensor are successfully fabricated on the /carbon electrode and integrated into one system by the dual-mode circuit.