Surface molecular imprinting on hybrid SiO2-coated CdTe nanocrystals for selective optosensing of bisphenol A and its optimal design

Abstract

Twenty molecular dynamics (MD) simulations of molecular imprinting prepolymerization systems had been performed to optimize the imprinting shell of the fluorescent sensor. The results revealed that the system with a Bisphenol A (BPA): 3-aminopropyltriethoxysilane (APTES): tetraethylorthosilicate (TEOS) mole ratio of 10:15:60 had the most stable template (T)-functional monomer (FM) cluster. Correspondingly, five kinds of imprinted and non-imprinted polymers were synthesized to assess the reliability and validity of the simulation results. Hybrid SiO2-coated CdTe NCs (HS-QD) were synthesized by a simple reflux procedure including a sol-gel reaction that resulted in the formation of a hybrid SiO2 layer with CdS-like clusters on a CdTe core. Based on the optimal component ratio of the prepolymerization system, MIP shells were anchored on the surface of HS-QD to build a fluorescent MIP sensor. A linear relationship between relative fluorescence intensity and the concentration of BPA had been obtained covering the concentration range of 0.05–10μmolL−1 with a limit of detection of 6nmolL−1. The feasibility of the fluorescent sensor was successfully evaluated through the analysis of BPA in river water and milk. The recoveries are above 96.31%, and the relative standard deviation (RSD) ranged from 1.55% to 2.78%.