基于新型发夹核酸探针和G-四链体/血红素脱氧核酶的多功能生物传感器  

A New Multifunctional Biosensor Based on a Hairpin Oligonucleotide Probe and G-Quadruplex/Hemin DNAzyme

作　　者：王蕾[1] 宋吉祥 刘兴奋[1] 黄艳琴[1] 范曲立[1] WANG Lei;SONG Ji-Xiang;LIU Xing-Feng;HUANG Yan-Qin;FAN Qu-Li(Institute of Advanced Materials,Jiangsu Key Laboratory for Biosensors,State Key Laboratory for Organic Electronics and Information Displays,Nanjing University of Posts&Telecommunications,Nanjing 210023,China)

机构地区：[1]南京邮电大学,有机电子与信息显示国家重点实验室,江苏省生物传感材料与技术重点实验室,信息材料与纳米技术研究院,南京210023

出　　处：《分析化学》2024年第8期1123-1131,共9页Chinese Journal of Analytical Chemistry

基　　金：江苏高校优势学科建设工程项目(No.YX030003);南京邮电大学科研项目(Nos.NY222151,NY221091)资助。

摘　　要：以发夹核酸探针(HP)为识别元件,基于靶介导的DNA构象转换,构建了一种用于检测血红素和血红蛋白的荧光“turn-on”模式的生物传感器。以游离HP为分子信标探针,供体与受体之间可发生高效荧光共振能量转移,导致荧光猝灭;当探针的富G序列在血红素诱导下形成稳定的G-四链体/血红素复合物时,供体与受体之间的距离拉大,荧光信号恢复。荧光法对血红素和血红蛋白的检出限分别为283和109 pmol/L。进一步,基于G-四链体/血红素复合物的类过氧化物酶活性以及L-半胱氨酸对酶活性的抑制,实现了对L-半胱氨酸的可视化分析,检出限为3.6μmol/L,低于细胞内半胱氨酸的正常水平(30~200μmol/L)。这种多功能生物传感平台具有检测快速、简便和灵敏的优点,在生物分析、药物筛选和疾病诊断等领域具有潜在的应用价值。A new multifunctional fluorescent"turn-on"biosensor was constructed based on a guanine-rich hairpin probe and G-quadruplex/hemin DNAzyme.The probe was labeled with quencher and fluorescein at 5′and 3′terminus,respectively.In the absence of the target,the probe form hairpin structure and the fluorescence of the fluorescein was quenched by the quencher.However,in the presence of the target,the hairpin structure transformed to G-quadruplex and the fluorescence was recovered.By monitoring the fluorescence of the probe before and after combining with the target,both hemin and hemoglobin were detected rapidly and conveniently with high sensitivity.The limit of detection for hemin and hemoglobin were estimated to be 283 pmol/L and 109 pmol/L,respectively.The specific interaction between the DNA probe and hemin were investigated via absorption and fluorescence spectra.Furthermore,L-cysteine was detected with naked eyes based on the peroxidase-like activity of the new G-quadruplex/hemin DNAzyme.The limit of detection for L-cysteine was estimated to be 3.6μmol/L,which was lower than the normal level of intracellular L-cysteine(30–200μmol/L).The method developed here was rapid,simple and sensitive for detection of hemin,hemoglobin and L-cysteine,demonstrating great potential in bioanalysis,drug screening,and disease diagnosis.

关 键 词：G-四链体 脱氧核酶 血红素 血红蛋白 生物传感器 

分 类 号：Q503[生物学—生物化学] TP212.3[自动化与计算机技术—检测技术与自动化装置] O657.3[自动化与计算机技术—控制科学与工程]