基于主客体识别作用构建的电化学发光传感器检测丹参中汞离子

使用联吡啶钌(Ru(bpy)2+3)/β-环糊精-金纳米粒子(β-CD-AuNPs)/全氟磺酸(Nafion)复合物和二茂铁标记(Fc)的DNA探针(Fc-DNA)构建了电化学发光(Electrochemiluminescence,ECL)生物传感器,将其用于检测中药材丹参中的汞离子。该传感器包含ECL发光基底和ECL强度开关两部分,将Ru(bpy)2+3/β-CDAu NPs/Nafion组装到玻碳电极(GCE)上构成发光基底,产生稳定的ECL信号; Fc-DNA探针作为ECL信号开关,通过分子识别策略设计,利用β-CD与Fc的主客体相互作用与β-CD-AuNPs相连。该检测方法和以往的汞离子检测方法相比,具有背景信号低、选择性高、仪器简单、操作快速等特点。该"Off-On"电致化学发光生物传感器在0. 04～800 ng/m L范围内对Hg2+具有良好的线性响应,检测限为0. 02 ng/m L(S/N=3)。

A New Type of Electrochemiluminescence Sensor for Detection of Mercury Ion in Chinese Medicinal Materials Danshen Based on Host-Guest Interaction

A new type of “Off-On” electrochemiluminescence(ECL) biosensor using Ru(bpy)32+/β-CD-AuNPs/Nafion complex and ferrocene-labeled DNA(Fc-DNA) was designed to detect mercury ions in Chinese medicinal materials Danshen. The ECL biosensor includes an ECL substrate and an ECL signal switch. Ru(bpy)32+/β-CD-AuNPs/Nafion complex modified glassy carbon electrode was used as the ECL substrate, which could bring about a clear and stable ECL signal by Ru(bpy)32+, and hairpin-like Fc-DNA probe acted as the ECL signal switch, which was designed by molecular recognition strategy and attached to β-CD-AuNPs through host-guest interaction between β-CD and ferrocene . Compared with previous methods of mercury ion detection, this method has the advantages of convenient operation, high sensitivity, good repeatability and low detection limit. The ECL biosensor offered good linear responses for Hg²⁺ in the range of 0.04~800 ng/mL with a detection limit of 0.02 ng/mL(S/N=3).