▎ 摘　　要

Here, a molecularly imprinted electrochemical quartz crystal microbalance (MIP-EQCM) sensor for aspartame is developed by grafting the aspartame-imprinted polymeric matrix of chitosan on gold-coated quartz crystal electrode. Chitosan nanoparticles being biocompatible, biodegradable and also having large surface area provide a better platform by forming a well-dispersed composite suspension with graphene. Additionally graphene facilitates direct electron transfer to electrode surface for electrochemical study because of having enhanced electrical conductivity. This EQCM-MIP sensor was characterized by atomic force microscopy, contact angle measurements, cyclic voltammetry and differential pulse voltammetry (DPV). The obtained MIP showed high affinity to aspartame. A reliable method for analysis of aspartame in real and commercial samples was achieved by coupling EQCM-MIP with DPV. Linear relationship with R-2=0.9749 (EQCM) and R-2=0.9760 (DPV) on binding of aspartame at various concentrations was observed. Detection limit of 0.45 mu gmL(-1) (EQCM) and 0.07 mu gmL(-1) (DPV) of the fabricated sensor shows that high sensitivity and high selectivity among various structural analogues of aspartame were also achieved. The improved detection limit is promising for determination of trace amount of aspartame. This demonstrates good memory capacity of this EQCM sensor. High recovery percentage and applicability of EQCM-MIP sensor in real matrices and commercial samples offers good potential for various applications.