Microfluidic Paper-Based Multiplexing Biosensors for Electrochemical Detection of Metabolic Biomarkers

Paper-based microfluidic devices, which have emerged as a low-cost analytical platform technology, promise simple yet powerful solutions for point-of-care (POC) disease diagnostics. In this chapter, we present a microfluidic paper-based electrochemical biosensor array capable of multiplexed detection of physiologically related metabolic markers. Compared with existing paper-based electrochemical devices, our design consists of a multiplexing array of eight electrochemical biosensors and works together with a portable, custom-made potentiostat for signal readout. The integrated platform, including the paper-based biosensor array and the portable potentiostat, is able to detect multiple target markers from one sample and carry out multiple measurements for each marker. Based on this platform, we conduct the detection of three metabolic biomarkers (i.e., glucose, lactate, and uric acid) in artificial urine, and achieve analytical performance comparable to existing commercial and paper-based analytical devices. As an integrated electrochemical system, the proposed multiplexing biosensor array will permit rapid and inexpensive disease diagnosis at the POC and/or in resource-limited regions.