Langmuir, 41, 19472−19480 (2025)
MoS2/TiO2 p−n-Type Heterojunction as a Photoelectrochemical Biosensor for Detecting Dopamine
Jing Tian1, Yue-Liu Li2, Peng Zhao1, Jian-Xun Dong3,*, Zhuo-Hao Li1, Yi-Lin Zheng1, Huan-Huan Yu1, Zhixin Hu4,*, Shou-Min Zhang1 and Bao-Lin Zhu1,*
1 College of Chemistry, The Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), National Demonstration Center for Experimental Chemistry Education, Nankai University, Tianjin 300071, China.
2 Haihe Lab of ITAI Tianjin, Tianjin 300450, China.
3 Henan Province Crystal Silicon Cutting Fine Micro Powder Engineering Technology Research Center, Pingdingshan 467000, China.
4 Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, Center for Joint Quantum Studies, Tianjin University, Tianjin 300072, China.
* djxun518@126.com, zhixin.hu@tju.edu.cn, zhubaolin@nankai.edu.cn
Abstract
Dopamine is a crucial neurotransmitter associated with neurological regulation and requires precise detection due to its concentration-dependent correlation with neurological disorders. In this work, a novel photoelectrochemical (PEC) sensor based on MoS2/TiO2 nanotubes (MoS2/TiO2 NTs) with p-n heterojunction nanocomposite was prepared through hydrothermal method. The constructed p-n heterojunction effectively enhanced charge separation efficiency, as systematically verified by multidimensional characterization including XRD, SEM, TEM, XPS, EIS, PL, UV−vis, M−S, etc. Under visible-light illumination, the optimized sensor demonstrated exceptional dopamine detectionperformance with a low detection limit of 0.074 μM (S/N = 3) in the range of 1−100 μM. This platform exhibited remarkable operational stability, selectivity, and fast response characteristics. Based on electrochemical analysis and density functional theory calculations, the PEC enhancement mechanism was revealed. This work provides new insights into heterojunction engineering for neuroimaging biomarker detection.
