A portable digital-control electrochemical system with automatic ohmic drop compensation for fast scan voltammetry and its application to ultrasensitive detection of chromium(III)

Abstract

In this work, a portable digital-control electrochemical system with automatic ohmic drop compensation for fast scan voltammetry was developed. The whole system consists of waveform generator module, detection module, power management module, display module, WiFi module and keying module, and it is digitally controlled. Based on the positive feedback technology and the control of microcontroller, ohmic drop could be 100% compensated automatically. Performance and behavior of this system are tested with dummy cells and an actual electrochemical cell using the redox reaction of ferrocene as a model, it was found that the highest scan rate 400 V/s could be achieved. And, it was applied to ultrasensitive detection of chromium(III), with a limit of detection of 0.3 pmol/L. In addition, it is portable because of light weight and small volume. Thus, this portable digital-control electrochemical system with automatic ohmic drop compensation opens the avenue for extensive research and application of fast scan voltammetry, especially in the construction of ultrasensitive sensors.