Sensitive and enzyme-free detection for single nucleotide polymorphism using microbead-assisted toehold-mediated strand displacement reaction  

作　　者：Jia-Bao Long Ying-Xin Liu Qing-Feng Cao Qiu-Ping Guo Shu-Ya Yan Xiang-Xian Meng 

机构地区：[1]College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University [2]Department of Bioengineering and Environment Science, Changsha University

出　　处：《Chinese Chemical Letters》2015年第8期1031-1035,共5页中国化学快报（英文版）

基　　金：supported by National Natural Science Foundation of China(No.21275043);National Basic Research Program of China under Grants(No.2009CB421601)

摘　　要：This report described a free-enzyme, convenient and inexpensive genotyping biosensor capable of detecting single nucleotide polymorphism at normal temperature based on the combination of toeholdmediated strand displacement reaction（toehold-SDR） and microbead-capture technique. The biosensor consists of a pre-hybridized strand formed by a reporter probe and a capture probe. In the presence of a mutant sequence, there is no toehold-mediated strand displacement and the reporter probe cannot be released from the pre-hybridized strand. Microbeads capture the fluorescent pre-hybridized strand through biotin–streptavidin interaction, so microbeads give out significant fluorescence signal, while there is no fluorescence in the solution. However, in the presence of a matched target, the strand displacement is effectively initiated and the reporter probe is released from pre-hybridized strand. After adding microbeads, the solution produces bright fluorescence, while microbeads have no obvious signal.Genotypes are identified conveniently according to the fluorescence intensity of the solution. The method provides a simple and inexpensive strategy to detect point mutation. Moreover, this biosensor shows the linear relationship in the range of 1–40 nmol/L and reaches a detection limit of 0.3 nmol/L.？ 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.Published by Elsevier B.V. All rights reserved.This report described a free-enzyme, convenient and inexpensive genotyping biosensor capable of detecting single nucleotide polymorphism at normal temperature based on the combination of toeholdmediated strand displacement reaction（toehold-SDR） and microbead-capture technique. The biosensor consists of a pre-hybridized strand formed by a reporter probe and a capture probe. In the presence of a mutant sequence, there is no toehold-mediated strand displacement and the reporter probe cannot be released from the pre-hybridized strand. Microbeads capture the fluorescent pre-hybridized strand through biotin–streptavidin interaction, so microbeads give out significant fluorescence signal, while there is no fluorescence in the solution. However, in the presence of a matched target, the strand displacement is effectively initiated and the reporter probe is released from pre-hybridized strand. After adding microbeads, the solution produces bright fluorescence, while microbeads have no obvious signal.Genotypes are identified conveniently according to the fluorescence intensity of the solution. The method provides a simple and inexpensive strategy to detect point mutation. Moreover, this biosensor shows the linear relationship in the range of 1–40 nmol/L and reaches a detection limit of 0.3 nmol/L.？ 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.Published by Elsevier B.V. All rights reserved.

关 键 词：strand capture biosensor convenient detecting capable inexpensive reporter bright matched 

分 类 号：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]