Validating a Smartphone-Powered NFC Bipotentiostat to Enable Dual-Working Electrode Measurements for Point-of-Care Electrochemical Biosensing

Abstract Electrochemical biosensors have emerged as attractive point-of-care testing platforms that provide rapid, quantitative results without expensive, bulky instrumentation. Sensors that use near-field communication (NFC) potentiostats have specifically gained traction because they are low-cost, portable, and battery-free, using a smartphone to passively transfer power and data. While many NFC potentiostat-driven sensors have been developed, these sensors can only measure one working electrode at a time, limiting their usefulness for applications that require detection of multiple analytes. To address this limitation, we demonstrate the first example of an NFC potentiostat used in bipotentiostat mode to achieve dual measurements from two working electrodes in an electrochemical immunoassay. Parameters for the chosen potentiostat, the SIC4341 developed by Silicon Craft Technology PLC, were optimized, and comparable electrochemical performance of the NFC bipotentiostat mode and a traditional bipotentiostat was demonstrated. The NFC bipotentiostat mode was then used to concurrently collect a blank and sample measurement for our previously developed magnetic bead-based electrochemical surrogate virus neutralization test (esVNT). When comparing both the mono-channel and bipotentiostat modes of the NFC and traditional potentiostats, highly similar performance was confirmed, establishing the NFC potentiostat as an important alternative for low-cost and portable point-of-care testing.