A molecularly-imprinted-electrochemical-sensor modified with nano-carbon-dots with high sensitivity and selectivity for rapid determination of glucose

In this work, a novel molecularly imprinted electrochemical sensor (MIECS) based on a glassy carbon electrode (GCE) modified with carbon dots (CDs) and chitosan (CS) for the determination of glucose was proposed for the first time. The use of the environmental-friendly CDs and CS as electrode modifications improved the active area and electron-transport ability substantially, while 3-aminobenzeneboronic acid was used as a functional monomer and glucose as template for the fabrication of molecularly imprinted polymer (MIP) film to detect glucose via differential pulse voltammetry. Transmission electron microscope, Fourier transform infrared spectroscopy, energy dispersive x-ray spectrometry, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were applied to characterize the fabricated sensor. Experimental conditions such as molar ratio of functional monomer to template, volume ratio of CDs to CS, incubation time and elution time were optimized. By using glucose as a model analyte, the MIECS had two assay ranges of 0.5–40 μM and 50–600 μM, and fairly low limit of detection (LOD) of 0.09 μM (S/N = 3) under the optimized conditions. The MIECS also exhibited excellent selectivity, good reproducibility, and stability. The proposed sensor was successfully applied to a preliminary test for glucose analysis in real human blood serum samples.