Figure 1.

A microfluidic paper-based electrochemical biosensor array that interfaces with a custom-made handheld potentiostat for multiplexed detection of metabolic biomarkers. (A) A paper-based electrochemical biosensor array (1 × 8). (B) A microcontroller-based multiplexing potentiostat mounted with a paper-based biosensor array. The potentiostat has eight measurement channels, and each channel is connected to a group of three sensing electrodes through metal clamps. CE: counter electrode. WE: working electrode. RE: reference electrode. (C) Schematic diagram of the potentiostat architecture with eight measurement channels. (D) A photograph of the paper-based biosensor array inserted into the potentiostat.