| 基于核酸适配体功能化荧光氧化石墨烯的免标记“Turn-off”型Hg2+传感器研究 |
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| 基金项目:国家自然科学基金项目(21005067)；湖南省自然科学基金资助项目(2019JJ40055)；湖南省教育厅资助科研项目(17A044,16B060) |
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| 中文摘要:利用湿化学法制备出具有一定荧光性能的氧化石墨烯(GO)负载金纳米颗粒(AuNPs)复合材料(GO@AuNPs)，并将巯基化单链富T核酸适配体(aptamer)结合在该复合材料的金纳米颗粒表面，形成aptamer功能化氧化石墨烯-金纳米颗粒复合物(aptamer-GO@AuNPs)。当汞离子存在时，由于7个T-Hg2+-T结构的配位作用，aptamer折叠形成刚性的发夹状双链DNA结构，并使Hg2+靠近石墨烯表面(少于1 nm)，使得电子可沿着双链DNA通道从石墨烯转移到汞离子，从而猝灭氧化石墨烯的荧光，由此构建了一种基于石墨烯荧光猝灭的“turn off”型荧光传感器。考察了多种因素对检测体系的影响，在最优实验条件下，此方法对Hg2+的线性检测范围为0.5~80 nmol/L，检出限为0.3 nmol/L。应用于环境水体样品中Hg2+的检测，加标回收率为96.0%~105%，相对标准偏差为1.4%~3.2%。该方法操作简单，有较强的抗干扰能力，灵敏度和选择性高，不需要标记，检测快速，可用于环境水体样品中Hg2+的高灵敏检测。 |
| 中文关键词:氧化石墨烯；核酸适配体；金纳米颗粒；免标记 Hg2+；荧光猝灭 |
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| Label-free Detection of Hg2+ Using a “Turn-off”Fluorescent Sensor Based on Aptamer Functionalized Graphene Oxide |
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| Abstract:In this study,a “turn off” fluorescent sensor based on aptamer functionalized grapheme oxide(GO) decorated gold nanoparticles(AuNPs) composites was developed for the detection of Hg2+.Firstly,the GO@AuNPs with certain fluorescence properties were fabricated by wet chemical method,then the sulfhydryl modified single chain T-rich nucleic acid DNA(aptamer) was immobilized on the surface of gold nanoparticles to form aptamer functionalized graphene oxide decorated gold nanoparticles complexes(aptamer-GO@AuNPs).In the presence of Hg2+,due to the coordination of seven T-Hg2+-T structures,T-rich aptamer was folded to form a rigid and double stranded hairpin structure,making coordinated Hg2+ close to the graphene surface(less than 1 nm).In that case,electrons could transfer from graphene to mercury ion along the double stranded DNA channel,which caused the graphene fluorescence quenched.Based on this,a “turn-off” fluorescence sensor was constructed.Under the optimal experimental conditions,the linear detection range for Hg2+ was 0.5-80 nmol/L,and the detection limit was 0.3 nmol/L.The method was applied in the detection of Hg2+ in environmental water samples.The recoveries ranged from 96.0% to 105% with the relative standard deviations of 1.4%-3.2%.With the advantages of simple operation,strong anti-interference,high sensitivity and selectivity,label-free and rapid detection,the method could be used for the high sensitive detection of Hg2+ in environmental water samples. |
| Key Words:graphene oxide aptamer gold nanoparticles label-free Hg2+ fluorescence quenching |
| 引用本文：杨梅，张何,雷湘玲，傅昕，王青，周宁涛.基于核酸适配体功能化荧光氧化石墨烯的免标记“Turn-off”型Hg2+传感器研究[J].分析测试学报,2019,38(10):1200-1206. |
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