Ultrasensitive ECL aptasensing of kanamycin based on synergistic promotion strategy using 3,4,9,10-perylenetetracar-boxylic-l-cysteine/Au@HKUST-1

Abstract

Herein, a sensitive and selective electrochemiluminescence (ECL) aptasensor was designed using Au@HKUST-1 as accelerator towards the perylene derivative (PTC-Cys)/peroxydisulfate (S2O82−) system for kanamycin (KAN) assay. Firstly, the PTC-Cys was prepared by covalently binding l-cysteine to 3,4,9,10-perylenete-tracarboxylic acid, which was acted as the luminophore. Then Au@HKUST-1could play the part of effective catalyst to accelerate the electrochemical reduction process of S2O82−to produce more sulfate radical anions (SO4•-), thus the ECL signal of the compound was noticeably raised by 2.4 times in comparison with that in which only luminophore and S2O82− are present, achieving signal amplification of the ECL system. In the presence of KAN, aptamer was pulled down from the sensing interface, achieving a considerable enhancement of ECL intensity in S2O82− solution. Upon the optimal condition, our proposed strategy can quantify the concentration of KAN from 1.0 × 10−13 to 1.0 × 10−8 M with low limit of detection of 4.2 × 10−14 M (S/N = 3).Besides, our proposed ECL aptasensor exhibited excellent sensitivity, stability and specificity, and could be successfully applied to detect KAN in practical samples, which proved its potential to detect other antibiotics in food security.