基于双重信号放大策略的生物传感器用于汞离子的灵敏可视化检测  

Highly Sensitive Biosensor for Visual Detection of Hg^(2+)Based on Dual Signal Amplification Strategy

作　　者：王玲丽 杨通 黄龙 张金[1] 胡蓉[1] 杨云慧[1] 杨建梅[1] 赵焱[1] WANG Ling-Li;YANG Tong;HUANG Long;ZHANG Jin;HU Rong;YANG Yun-Hui;YANG Jian-Mei;ZHAO Yan(College of Chemistry and Chemical Engineering,Yunnan Normal University,Kunming 650500,China)

机构地区：[1]云南师范大学化学化工学院,昆明650500

出　　处：《分析化学》2024年第11期1678-1686,共9页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(No.22364023);云南省基础研究计划项目(Nos.202301AT070074,202201AU070056);云南省教育厅科学研究基金项目(No.2021J0436);云南师范大学博士科研启动项目(No.2020ZB009)资助。

摘　　要：重金属汞对人类的生活环境和身体健康构成了严重威胁,因此,构建简单灵敏的汞离子(Hg^(2+))检测方法尤为重要。本研究结合催化发夹自组装(CHA)和滚环扩增(RCA)两种高效信号放大技术,构建了具有双重信号放大功能的生物传感器,用于Hg^(2+)的高灵敏和高选择性定量检测。当目标物Hg^(2+)存在时,DNA辅助探针通过T-Hg^(2+)-T碱基错配杂交引发CHA反应(第一重信号放大),生成的DNA双链产物进一步引发RCA反应,生成大量的G-四链体重复序列(第二重信号放大)。这种特殊的序列与氯化血红素(Hemin)孵育后形成具有类辣根过氧化物酶活性的Hemin/G-四链体DNA酶,可催化底物3,3',5,5'-四甲基联苯胺(TMB)发生氧化反应,使TMB由无色变成蓝色。由于结合了两种高效的信号放大策略,采用紫外-可见吸收光谱法可实现Hg^(2+)的高灵敏定量检测,检出限(LOD, 3σ)低至0.21 nmol/L。同时,通过裸眼观测溶液的颜色变化,可实现浓度为1 nmol/L的Hg^(2+)的可视化检测。此传感器具有优异的选择性,可用于复杂水样中Hg^(2+)的检测,为重金属污染物的检测提供了简单灵敏的分析平台,在环境监测领域具有潜在的应用价值。Because of serious toxic effects of mercury ion (Hg^(2+)) on the environment and human body, it is of greatsignificance to develop a simple and sensitive platform for Hg^(2+) detection. Herein, a colorimetric biosensor withdual signal amplification principle based on catalytic hairpin assembly (CHA) and rolling circle amplification(RCA) was constructed for sensitive and selective detection of Hg^(2+). The presence of target Hg^(2+) could initiate CHAreaction to form a double-stranded product via T-Hg^(2+)-T base mismatch hybridization (First signal amplification).The double-stranded products could further trigger the RCA reaction to generate massive G-quadruplex sequences(Secondsignal amplification).These special DNA sequences had obvious horseradish peroxidase (HRP)mimickingactivity after incubating with hemin, which could catalyze the conversion of colorless substrate 3,3′,5,5′-tetramethylbenzidine (TMB) to form blue colored product. Because of the combination of two efficient signalamplification strategies, a low detection limit (0.21 nmol/L, 3σ) was obtained by ultraviolet-visible absorptionspectrometry. At the same time, the visual detection of Hg^(2+) at concentration level of 1 nmol/L could be realized byobserving the color of the solution with naked eyes. In addition, the proposed biosensor showed high specificity fordetection of Hg^(2+), and could also be utilized to monitor Hg^(2+) in real water samples. The sensing strategy provided asimple and sensitive platform for detection of heavy metal pollutants, showing great application potential inenvironmental monitoring.

关 键 词：催化发夹自组装 滚环扩增 生物传感器 可视化检测 汞离子 

分 类 号：X832[环境科学与工程—环境工程] O657.3[理学—分析化学] TP212.3[理学—化学]