Facile construction of reduced graphene oxide–carbon dot complex embedded molecularly imprinted polymers for dual-amplification and selective electrochemical sensing of rutoside†
In this article, reduced graphene oxide–carbon dots (RGO–CDs) were deposited on the surface of a glassy carbon electrode (GCE). RGO–CDs and rutoside were facilely embedded into poly(pyrrole) through electrochemical polymerization. After elution of rutoside, a novel sensing system of molecularly imprinted polymers (MIPs) was developed and used for rutoside detection. The use of RGO–CDs markedly improved the electrochemical signal responses to electroactive rutoside, which thus facilitated the sensitive electrochemical sensing of rutoside. The as-synthesized MIPs/RGO–CDs/GCE sensing system was characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The electrochemical responses of the sensing system were studied and optimized. Under optimal conditions, MIPs/RGO–CDs/GCE showed a nearly linear relationship between the change in peak current intensities and the rutoside concentration in the 0.01–6.5 μM range (R2 = 0.9932), with a low limit of detection of 3 nM. Moreover, the sensing system exhibited a highly selective and sensitive electrochemical response to rutoside, over potential interferents. In real human serum samples, the sensing system exhibited superior performance for rutoside detection, accompanied by high detection stability and recovery. These results proved the significant potential of MIPs/RGO–CDs/GCE for efficient determination of rutoside in real samples.