Flexible Ti3C2Tx MXene Regulated Photoelectrochemical Sensing Platform for Sensitive Monitoring of Dopamine

Abstract Flexible photoelectrochemical (PEC) based sensors have been extensively investigated for noninvasive healthcare monitoring. However, known electrode materials struggle to combine technologically relevant metrics of high sensitivity and flexibility due to their low electrical conductivity and fragile mechanical properties. Herein, a flexible PEC‐based sensor for dopamine (DA) detection is presented by integrating highly conductive and flexible MXene between CdS quantum dots and g‐C 3 N 4 with suitable energy level matching. Theoretical calculations reveal that the interfaces of constructed PEC electrodes with enhanced electronic conductivity derived from MXene not only improve the electron transfer kinetics, but form built‐in electric fields at the interfaces, facilitating the separation efficiency of electron–hole pairs. As a result, the as‐prepared sensors display the combined advantages of a wide detection range (1 nM–0.1 mM), low detection limit (0.48 nM), high stability, selectivity, and repeatability for DA detection. Building on these metrics, a scalable screen‐printing method is further developed for integrating the sensors on flexible platforms. These all‐integrated PEC‐based sensors exhibit stable photocurrent signals under different bending angles and bending cycles. Therefore, this work demonstrates the scalable development of flexible PEC‐based sensors for the sensitive detection of DA and holds promise for the future development of noninvasive healthcare monitoring.