Miniaturized Reverse Electrodialysis-Powered Biosensing System

Abstract

Recently, there have been great advances in developing low cost and disposable sensing platforms for disease diagnosis, e.g. paper-based sensors and microfluidics, which can be ultimately applicable in developing countries. However, in order to provide diagnostic information, many of those platforms are not capable of standing alone, and thus require such electric power sources for their operation. In this regard, we introduce an eco-friendly, disposable, and miniaturized reverse electrodialysis (RED) patch as an electric power source for electrochemical sensing of a biomarker with electrochemiluminescence (ECL) reporting. The flexible RED patches were simply fabricated by using ion-exchange membranes (IEMs) and double-sided adhesive tapes. Any desired voltage was readily obtained from the RED patches by altering the number of IEMs and a salinity ratio. We integrated the RED patch with a bipolar electrode-possessing microfluidic chip, and then, as a proof-of-concept, successfully detected a cancer biomarker, prostate-specific antigen, by observing ECL emissions with the naked eyes. The miniaturized RED-powered biosensing system can be easily combined with any sensing platform, thereby increasing practical feasibility in developing countries.