Design of potentiostat and current mode read-out amplifier for glucose sensing

Abstract

The paper presents a novel design potentiostat and read-out amplifier circuits for glucose sensing. The performance of proposed design is evaluated by using a power supply of 1.5 V in Semi-Conductor Laboratory (SCL) 0.18 $\mu$m CMOS technology. There are two main advantages of the proposed design. First is reference voltage required across sensor reference electrode and working electrode, which is supplied by MOS transistors threshold voltage and the second is multioutput transconductance amplifier (MTA) programmable gain which is enhanced by transconductance (gm) boosting technique. It is useful to readout small magnitude sensor current. The proposed design is found suitable for the glucose concentration measurement from 50 mg/dl to 225 mydl. It is observed that the linear range is found for the sensor current from 40 nA to 210 nA i.e. electrode resistance from 6 M$\Omega$ to 30 M$\Omega$ approximately. The maximum power consumption of the proposed design is 124 $\mu$Watt.