Modular, lightweight, wireless potentiostat-on-a-disc for electrochemical detection in centrifugal microfluidics

Interfacing electrochemical sensors in a lab-on-a-disc (LoD) system with a potentiostat is often tedious and challenging. We here present the first multichannel, modular, lightweight, and wirelessly powered, custom-built potentiostat-on-a-disc (PoD) for centrifugal microfluidic applications. The developed potentiostat is in the form factor of a typical digital video disc (DVD) and weighs only 127 g. The design of the potentiostat facilitates easy and robust interfacing with the electrodes in the LoD system, while enabling real-time electrochemical detection during rotation. The device can perform different electroanalytical techniques such as cyclic voltammetry, square wave voltammetry, and amperometry while being controlled by custom-made software. Measurements were conducted with and without rotation using both in-house fabricated and commercial electrodes. The performance of the PoD was in good agreement with the results obtained using a commercial potentiostat with a measured current resolution of 200 pA. As a proof of concept, we performed a real-time release study of an electrochemically active compound from microdevices used for drug delivery.