A Simple and Rapid Fluorescent Sensor Based on MoS₂ Quantum Dots for Dopamine Detection

In this study, molybdenum disulfide quantum dots (MoS₂ QDs) were synthesized via a one-step hydrothermal method, and a simple, rapid fluorescent sensing platform for dopamine (DA) detection was established based on fluorescence quenching. Experimental results demonstrated that DA is oxidized to dopamine quinone under alkaline conditions, leading to fluorescence quenching of MoS₂ QDs through the synergistic effects of inner filter effect (IFE) and electron transfer (ET). The optimized method exhibited a linear response at 434 nm (200-600 µM, R² = 0.9980) with a detection limit of 4 µM. The sensor showed high selectivity for DA and was successfully applied to spiked recovery tests in human urine samples, achieving recoveries of 95-104.6%. The stability of MoS₂ QDs, simplicity of preparation, and practical applicability highlight its potential for DA analysis in complex biological samples.