摘要
构建了铅离子(Pb^2+)功能核酸比色生物传感器,用于可视化检测水中Pb^2+。利用GR-5脱氧核酶对Pb^2+特异性识别,对底物链切割,同时通过巧妙的核酸设计,将GR-5脱氧核酶的切割产物与显色模板结合形成G-四链体,其中显色模板主要包括与切割产物核酸的序列互补区、富含鸟嘌呤的G四链体形成区以及连接二者的间隔臂。在Pb^2+存在时,GR-5脱氧核酶的底物链被识别、切割并释放,此切割产物与显色模板结合,并转化成G-四链体,由于G-四链体在特定条件下具有类过氧化物酶活性,可催化H2O2和3',3',5,5'-四甲基联苯胺(TMB)显色,基于此构建了Pb^2+功能核酸比色生物传感器。优化的实验条件为:GR-5脱氧核酶的底物链和酶链最优配比1∶1,切割时间3 min,显色模板浓度5μmol/L,最适TMB用量50μL。本传感器检测Pb^2+的线性范围为25 nmol/L^2.5μmol/L,线性关系为y=0.039x+0.3486(R=0.9904),检出限为10.1 nmol/L(3σ),用于自来水中Pb^2+的检测,加标回收率为98.2%~115.5%。本方法具有灵敏度高、特异性强、操作简单等优点,具有良好的应用前景。
A method for visual detection of Pb 2+in water based on lead ion(Pb^2+)functional nucleic acid colorimetric biosensor was developed.The specific recognition and cleavage of Pb^2+by GR-5 deoxyribozyme was carried out,and the cleavage products of GR-5 deoxyribozyme were combined with the color templates to convert into a G-quadruplex by clever nucleic acid design,wherein the color templates mainly included a complementary region to the cleavage product nucleic acid sequences,a guanine-rich G quadruplet forming region,and a spacer arm.In the presence of Pb^2+,the substrate chain of the GR-5 deoxyribozyme was recognized to be cleaved and released,and the cleavage product was converted into a G-quadruplex by binding to a chromogenic template,since the G-quadruplex was under specific conditions.The peroxidase-like activity catalyzed the color development of H2O2 and 3,3',5,5'-tetramethylbenzidine(TMB),thus completing the construction of the Pb^2+functional nucleic acid colorimetric biosensor.Through a series of conditions optimization,it was found that the optimal ratio of substrate chain and enzyme chain of GR-5 deoxyribozyme was 1∶1,the cleavage time was 3 min,the color template concentration was 5μmol/L,and the optimal TMB concentration was 50μL.Under the optimal conditions,the detection range of Pb^2+was 25 nmol/L-2.5μmol/L,the linear relationship was y=0.039x+0.3486(R=0.9904),and the lowest detection concentration was 10.1 nmol/L(3σ).The recoveries were 98.2%-115.5%.The proposed method had a good application prospect due to its high sensitivity,strong specificity and simple operation.
作者
李宸葳
林晟豪
杜再慧
孙春燕
许文涛
LI Chen-Wei;LIN Sheng-Hao;DU Zai-Hui;SUN Chun-Yan;XU Wen-Tao(College of Food Science and Nutritional Engineering,China Agricultural University,Beijing 100083,China;College of Food Science and Engineering,Jilin University,Changchun 130062,China)
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2019年第9期1427-1432,共6页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金项目(No.31871875)资助~~
关键词
铅离子
功能核酸
可视化
G-四链体
生物传感器
Lead ion(Ⅱ)
Functional nucleic acid
Visualization
G-quadruplex
Biosensor
