【作者】 栾倩； 干宁； 李天华； 曹玉廷；

【Author】 Qian Luan;Ning Gan;Tianhua Li;Yuting Cao;State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Materials Science and Chemical Engineering, Ningbo University;

【机构】 宁波大学材化学院；

【摘要】 这里本文提出了一种基于单链DNA结合蛋白（SSB）和HRP标记的比色适配体传感器来检测食品中残留的氯霉素。为了构建该传感器,首先我们合成了金包覆的Fe₃O₄（Fe₃O₄@Au）,利用Au易修饰的性质,将单链DNA结合蛋白修饰在Fe₃O₄@Au表面形成磁性探针（Fe₃O₄@Au-SSB）;之后我们将Apt和HRP酶同时标记到核壳结构的SiO₂@Au表面来形成信号探针（Apt-SiO₂@Au-HRP）。随后SSB与Apt通过碱基互补配对结合形成该方案中的比色传感器。众所周知,HRP可以催化TMB-H₂O₂系统发生颜色变化。当目标物CAP存在时,Apt与氯霉素结合使得部分信号探针游离在上清液中,通过磁性分离,我们取上清液加入TMB-H₂O₂,由于上清液中存在大量HRP从而产生比色信号响应。我们利用紫外分光光度计来检测波长650nm处的吸光度与氯霉素的浓度呈线性正相关。该比色传感器通过SiO₂来富集AuNPs从而放大比色信号,得到了0.02ng mL^-1的检测限,具有较高的选择性和灵敏度。更多还原

【Abstract】 Herein, a selective and facile colorimetric aptasensor has been developed to detect trace antibiotics based on Apt and HRP labeled core-shell of Si O₂@Au as nanotracers. Firstly, the magnetic probe was prepared through the single stranded DNA binding protein labeled on Fe₃O₄@Au nanoparticles. Secondly, the preparation of nano-tracer was Apt and HRP labeled on core-shell SiO₂@Au. The composite probe was formed by the principle of complementary base pairing（the Apt on signal probe combine with the SSB on capture probe）. Upon the CAP adding to the solution, the aptamer on the nanotracer preferentially bounded with CAP, and then released CAP-Apt complex（which contained SiO₂@Au-HRP） to the supernatant. The supernatant containing numerous HRP could efficiently catalyze TMB-H₂O₂ system for the color development. The results of experimental demonstrated a broad linear range from 0.1 ng mL^-1 to 100 ng mL^-1 the low detection limit 0.02 ng mL^-1. Moreover, the colorimetric aptasensor with good selectivity, acceptable stability and reproducibility.更多还原