Nanoflower MoS2/rGO composite rich in edge defects for enhanced electrochemical sensing of nM-level dopamine

The development of electrochemical dopamine (DA) sensor with anti-interfering ascorbic acid and uric acid is challenging due to the presence of their overlapping electrical signals. Herein, MoS2 nanoflower assembled from ultrathin nanosheets were uniformly loaded on rGO substrate through one-step hydrothermal reaction. Then, the composite (MoS2/rGO) was modified on the surface of glassy carbon electrode (GCE) by a drop coating method, successfully assembling non-enzymatic electrochemical sensor for ultra-selective DA detection. The test results show that the MoS2/rGO/GCE probe exhibits good sensitivity (15.73 μA μM−1 cm−2), small limit of detection (13 nM) and wide range of detection (0.1 ∼ 110.0 μM) for DA in 0.1 M PBS medium (pH = 7.4), as well as good interference resistance, reproducibility and stability. This excellent sensing ability mainly stems from the synergistic effect of the prepared electrode material with abundant edge defects, small charge transfer resistance, large electrochemically active area, and more negative Zeta potential (–23.4 mV). Furthermore, the satisfactory and accurate detection of DA content in animal serums predicts its potential for practical applications in related biological aspects.