摘要：

银作为一种常见的重金属及贵金属，广泛应用于冶金、化工及生物医药等行业。实现对工业废水中银离子的高效分析，对银离子的定量回收及环境监测具有重要的指导意义。设计了一种氧化石墨烯-核酸传感器，基于氧化石墨烯吸附单链核酸分子探针以及猝灭荧光的性质而降低背景信号；在银离子的存在下，单链核酸探针因形成C-Ag⁺-C复合结构而解离氧化石墨烯表面并恢复荧光信号；进一步，在核酸酶（DNase Ⅰ）的作用下，完成银离子的循环反应，通过荧光信号的累积实现银离子的高灵敏度、高特异性检测。实验结果表明：荧光强度与银离子浓度呈线性关系（R²=0.998 7），线性范围为0.5~20 nmol/L，检测限为0.5 nmol/L。

关键词: 银离子检测, 氧化石墨烯, 核酸传感器, 高灵敏度, 高特异性

Abstract:

As a common heavy metal and precious metal, silver is widely used in metallurgical, chemical and biological medicine industries. It has important theoretical guiding significance for quantitative recovery of silver ion and environmental monitoring to realize the sensitive and specific detection of silver ions in industrial waste water. In this work, basing on GO adsorbing single chain nucleic acid molecules and quenching fluorescence signal to lower the background signals, a graphene oxide(GO) was designed. In the presence of silver ions, the nucleic acid molecules probe bind with silver ions, which based on the stability and specificity of C-Ag⁺-C structure, and away from GO, turning the fluorescence signal "on". Furthermore, under the action of DNase I, the cyclic reaction of silver ions was completed, and the high sensitivity and high specificity detection of silver ions was realized through the accumulation of fluorescence signal. The results showed that the fluorescence intensity was linear with the concentration of silver ion(R²=0.998 7), the linear range was 0.5-20 nmol/L, and the limit of detection was 0.5 nmol/L.

Key words: silver ions detection, graphene oxide, nucleic acid biosensor, high sensitivity, high specificity

中图分类号: 

• O661