文献类型：期刊文献

英文题名：Label-Free Detection of Sequence-Specific DNA Based on Fluorescent Silver Nanoclusters-Assisted Surface Plasmon-Enhanced Energy Transfer

作者：Ma, Jin-Liang[1];Yin, Bin-Cheng[1];Le, Huynh-Nhu[1];Ye, Bang-Ce[1,2]

机构：[1]East China Univ Sci & Technol, Biomed Nanotechnol Ctr, State Key Lab Bioreactor Engn, Lab Biosyst & Microanal, Shanghai 200237, Peoples R China;[2]Shihezi Univ, Sch Chem & Chem Engn, Xinjiang 832000, Peoples R China

年份：2015

卷号：7

期号：23

起止页码：12856

外文期刊名：ACS APPLIED MATERIALS & INTERFACES

收录：;EI(收录号：20152600963841);WOS:【SCI-EXPANDED(收录号:WOS:000356753500063)】；

基金：This work was jointly supported by the National Natural Science Foundation of China (Grants 21335003, 21421004, 21205040), the Key Grant Project of Chinese Ministry of Education (Grant 313019), the Shanghai Fund (Grant 12ZR1442700), the Fundamental Research Funds for the Central Universities, and Hitachi, Ltd.

语种：英文

外文关键词：DNA detection; surface plasmon enhanced energy transfer; fluorescent silver nanoclusters; gold nanoparticle; fluorescence enhancement

摘要：We have developed a label-free method for sequence-specific DNA detection based on surface plasmon enhanced energy transfer (SPEET) process between fluorescent DNA/AgNC string and gold nanoparticles (AuNPs). DNA/AgNC string, prepared by a single-stranded DNA template encoded two emitter-nucleation sequences at its termini and an oligo spacer in the middle, was rationally designed to produce bright fluorescence emission. The proposed method takes advantage of two strategies. The first one is the difference in binding properties of single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) toward AuNPs. The second one is SPEET process between fluorescent DNA/AgNC string and AuNPs, in which fluorescent DNA/AgNC string can be spontaneously adsorbed onto the surface of AuNPs and correspondingly AuNPs serve as "nanoquencher" to quench the fluorescence of DNA/AgNC string. In the presence of target DNA, the sensing probe hybridized with target DNA to form duplex DNA, leading to a salt-induced AuNP aggregation and subsequently weakened SPEET process between fluorescent DNA/AgNC string and AuNPs. A red-to-blue color change of AuNPs and a concomitant fluorescence increase were clearly observed in the sensing system, which had a concentration dependent manner with specific DNA. The proposed method achieved a detection limit of similar to 2.5 nM, offering the following merits of simple design, convenient operation, and low experimental cost because of no chemical modification, organic dye, enzymatic reaction, or separation procedure involved.