Novel Electrochemical Sensor Application for Dopamine and Preparation of N-rGO Micro-regionally Constrained WS2 Nanocomposite

Dopamine is an important neurotransmitter for organisms and affects their function, so monitoring and detecting dopamine levels are essential. Sensitivity and selectivity of electrochemical sensors for the detection of dopamine usually rely on hybrid nanocomposites. In this context, we designed a micro-regionally restricted hybrid nanocomposite by modulating the micro-nano structure. Using functional groups on nitrogen-doped reduced graphene oxide (N-rGO) to restrict the random growth of tungsten disulfide nanosheets, we obtained a 2D layered material with bidirectional structural support to achieve high specific surface and high activity for application in robust and novel dopamine electrochemical sensors. A facile electrochemical sensor for dopamine detection was fabricated by modifying a screen-printed carbon electrode with the nanocomposite. The sensor exhibits excellent performance of dopamine detection in the wide range of 1 μmol l−1–100 μmol l−1 with a detection limit of 0.2 μmol l−1 and a high sensitivity of 0.56 μA μmol−1 l−1. The optimized sensor shows a good selectivity, satisfactory long-term stability and reproducibility towards DA and a separation of peak potential of 142 mV with uric acid. In addition, the prepared sensor provides favorable recovery in human serum and artificial cerebrospinal solution (aSCF), indicating great potentials in electrochemical detection and biological sensing applications.