Open AccessSynthesis of CdTe Quantum Dots‐based Imprinting Fluorescent Nanosensor for Highly Specific and Sensitive Determination of Caffeic Acid in Apple Juices
Author(s) -
Long Ruiqing,
Li Te,
Wu Lihui,
Shi Shuyun
Publication year - 2020
Publication title -
efood
Language(s) - English
Resource type - Journals
ISSN - 2666-3066
DOI - 10.2991/efood.k.190802.003
Subject(s) - fluorescence , molecularly imprinted polymer , detection limit , tetraethyl orthosilicate , nanosensor , polymerization , caffeic acid , chemistry , nuclear chemistry , materials science , molecular imprinting , chromatography , selectivity , polymer , nanotechnology , organic chemistry , physics , quantum mechanics , antioxidant , catalysis
A facile method for the synthesis of molecularly imprinted polymers (MIPs) onto CdTe quantum dots (CdTe‐QDs@MIPs) was successfully developed, and for the first time used as a sensitive fluorescent nanosensor for specific and rapid determination of caffeic acid (CA) in apple juices. Sol–gel polymerization was selected to fabricate hydrophilic MIPs layer using 3‐(aminopropyl)triethoxysilane, tetraethyl orthosilicate, and CA as functional monomer, cross‐linker and template, respectively. Under optimum experimental conditions, smaller CdTe‐QDs@MIPs particles (48 nm) were synthesized with polymerization time at 2 min, which showed fast fluorescence quenching with response time at 3 min and high sensitivity with a limit of detection at 0.73 μg L −1 . The fluorescence intensity of CdTe‐QDs@MIPs presented excellent linearity with the concentration of CA in the range from 2 to 100 μg L −1 ( R 2 , 0.9980). The developed method showed good repeatability with batch‐to‐batch relative standard deviation at 3.31%, and excellent selectivity over structural analogues. The practicability of the as‐prepared CdTe‐QDs@MIPs was confirmed by the analysis of CA in apple juices with satisfactory recoveries from 93.3% to 108.3%, and precisions <2.1%. Results demonstrated that a rapid, selective, and sensitive fluorescent method was successfully developed to detect CA in food samples.