The Sensing Analysis of the Potentiometric Enzymatic RuO2 Biosensor Based on FPCB for Dopamine Detection

We present a differential-type enzymatic ruthenium dioxide (RuO2) biosensor designed for dopamine detection, with a focus on its application in wearable devices and flexible electronics. The sensor is based on flexible printed circuit boards (FPCBs) and features a RuO2 thin film as the sensing membrane modified with tyrosinase and Nafion. The RuO2 thin film was fabricated using a radio frequency sputtering system, and the biosensor exhibits exceptional sensitivity, with an average value of 77.58 mV/decade and a limit of detection (LOD) of
$0.12~\mu \text{M}$
for dopamine. One of its remarkable features is its selectivity, allowing precise dopamine detection even in the presence of common interfering substances found in urine samples. The practical utility of this biosensor is demonstrated through satisfactory dopamine recovery rates in artificial urine samples, ranging from 92.6% to 94.6%. Overall, our proposed RuO2 biosensor on FPCB offers a promising solution for accurate and selective dopamine detection, with potential applications in wearable devices and flexible electronics.