In this work, a specific molecularly imprinted polymer (MIP) electrochemical sensor was developed for the ultra-selective and sensitive determination of dopamine (DA). The MIP film was prepared by the electropolymerization of pyrrole in the presence of DA on the surface of a modified glassy carbon electrode (GCE) using a nanocomposite of f-MWCNTs-ZnO nanohybrids and graphene quantum dots (GQDs). The constructed sensor (MIP/f-MWCNTs-ZnO@GQDs/GCE) exhibits remarkable electrochemical performance, with effective electron transfer resulting from its interface catalytic action and a designed porous site structure. The reaction sites and mechanisms associated with DA were elucidated by analyzing its electrochemical behavior using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The results, supported by X-ray diffraction (XRD), Transmission electron microscopy (TEM), and field-emission scanning electron microscopy (FE-SEM), demonstrated the formation of MIP and NIP. Under optimized conditions, the MIP sensor exhibited a linear relationship with DA concentrations over an extensive linear range from 1×10−7 to 9×10−4 mol/L, achieving a detection limit of 4.25×10−8 mol/L (S/N = 3). Additionally, the sensor yielded good results in the quantification of DA in actual biological samples. The MIP/f-MWCNTs-ZnO@GQDs/GCE demonstrated notable stability, sensitivity, repeatability, reproducibility, and selectivity for the quantification of DA even when confronted with low and high concentrations of over-interfering compounds.
