Low-Cost Impedance Measurements for Lab-on-a-Chip Architectures: Towards Potentiostat Miniaturization

The development of miniaturized potentiostats capable of measuring in a wide range of conditions and with full characteristics (e.g., wide bandwidth and capacitive/inductive contribution to sensor’s impedance) is still an unresolved challenge in bioelectronics. We present a simple analogue design coupled to a digital filter based on a lock-in amplifier as an alternative to complex architectures reported hitherto. A low-cost, miniaturized and fully integrated acquisition electronic system was developed, tested for a fully integrated three-lead electrochemical biosensor and benchmarked against a commercial potentiostat. The portable potentiostat was coupled to an array of miniaturized gold working electrodes to perform complex impedance analyses for tumor necrosis factor α (TNF-α) cytokine detection. This wearable potentiostat is very promising for the development of low-cost point-of-care (POC) with low power consumption.
The research leading to these results has received funding from the European Union’s 7FP (SEA-on-a-CHIP, Grant Agreement No. 614168) and the European Union’s Horizon 2020 (HEARTEN, Grant Agreement No. 643694). R.P. acknowledges an FPU grant from the Spanish Ministerio de Educación, Cultura y Deporte.