基于纳米金标记-适配体识别的伏马菌素B_1检测新方法

Novel Methods for Fumonisins B1 Detection Based on AuNPs Labeling and Aptamer Recognition

摘要:

基于核酸适配体识别和纳米金变色效应构建了伏马菌素B1(FB1)的可视化检测新方法。实验以纳米金为载体,首先在纳米金表面组装巯基化的适配体互补短链DNA1/FB1-适配体复合物;当加入目标物时,适配体链与目标物结合,与互补短链DNA1发生解离;此时再加入纳米金标记的与适配体互补短链1互补的短链DNA2,二者杂交可导致纳米金粒子的聚集而使溶液颜色发生变化,进而实现目标物的可视化检测。通过条件优化,有效避免了由于盐浓度过高使纳米金发生聚集所产生的误差。同时在纳米金与短链DNA孵化时加入表面活性剂十二烷基硫酸钠(SDS),使NaCl浓度达到了500 mmol/L而纳米金颜色仍不发生改变,打破了以往熟化NaCl浓度100 mmol/L就使纳米金颜色发生变化的界限,使附着在纳米金上的DNA量扩大了3倍。方法检测线性范围为125～1 500 ng/L,检测限为125 ng/L。该方法已成功应用于啤酒中FB1的检测。

Abstract:

This work set up a new naked eye detection method for FB1 abased on the high identification function of DNA aptamer and the color changing effect of AuNPs.This assay method taked AuNPs as carrier and firstly linked to DNA1 and then assembled FB1-aptamer-DNA1-AuNPs complex throuth the hybridzation process between FB1-aptamer and DNA1-AuNPs.When added different concentrations of FB1,FB1-aptamer prefered to connect to FB1 and then subsequently additional DNA2 chain that matched with DNA 1 chain can hybrid with exposed DNA1 resulting in AuNPs aggregation.Thus the color changes from red to purple and blue could be observed by the naked eye.Optimal conditions avoided to much salt induced AuNPs aggregation caused error effectively.Furthermore,we added SDS in DNA1 or DNA2 chain connected to AuNPs to maintain the color of AuNPs and improved the concentration of NaCl to 500 mmol/L and DNA loading enlarge 3 times.This breaks the traditional boundary of 100 mmol/L NaCl can caused the color change of AuNPs.The linear range of the colorimetric aptasensor covers a large variation of FB 1 concentration from 125 ng/L to 1500 ng/L and the detection limit of 125 ng/L is obtained.