BATTERY-POWERED MINIATURE BIPOTENTIOSTATS FOR AMPEROMETRIC BIOSENSORS

The design and characterization of two miniature bipotentiostats for u se with amperometric biosensors is described. The bipotentiostats are powered by 9V batteries and have counter electrode potential swings of +/- 1.5 V and +/- 3.0 V. respectively. In the first, a voltage signal , proportional to the current generated by the sensor, is transferred to a data logger. In the second, the output signal is transmitted to a personal computer through an opto-coupler by pulse width modulation s o as to electrically isolate the system in or on the body from the ext ernal AC line. The devices accurately measure currents in the nA range and their output signals are stable for over 100 h. They are suitable for use in both in vitro and in vivo studies requiring accurate amper ometry.