A photoelectrochemical sensor based on copper-based metal organic framework derivatives for the homogeneous detection of L-cysteine

Due to their outstanding advantages, photoelectrochemical (PEC) sensors have gained significant attention, which can realize the rapid and accurate detection of target. However, the semiconductor as its core component has a strong influence on the analysis and detection performance. Herein, we developed a simple and efficient method to prepare heterojunction for the construction of PEC sensor detecting L-cysteine (L-Cys). The rod-like copper-based metal organic framework was prepared by room temperature synthesis method, which was used to derive rod-like CuO/Cu2O/C heterojunction with excellent photoelectric property. Due to L-Cys interacts with CuO/Cu2O/C heterojunction to form steric hindrance effect through Cu-S bond, which reduces the photocurrent signal and realizes the selective and homogeneous detection of L-Cys. Inspired by this steric strategy, a PEC sensing platform was fabricated by CuO/Cu2O/C heterojunction for the homogeneous detection of L-Cys, showing linear responses in the range of 0.2 μM to 50 μM with the detection limit of 0.12 μM. Our work shed light on the advancement of better PEC sensor and the method of constructing heterojunction.