文献类型：期刊文献

英文题名：Copper-Mediated DNA-Scaffolded Silver Nanocluster On-Off Switch for Detection of Pyrophosphate and Alkaline Phosphatase

作者：Ma, Jin-Liang[1];Yin, Bin-Cheng[1];Wu, Xin[3];Ye, Bang-Ce[1,2]

机构：[1]East China Univ Sci & Technol, 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;[3]Second Mil Med Univ, Shanghai Changzheng Hosp, Dept Rheumatol & Immunol, Shanghai 200433, Peoples R China

年份：2016

卷号：88

期号：18

起止页码：9219

外文期刊名：ANALYTICAL CHEMISTRY

收录：;EI(收录号：20163902847719);WOS:【SCI-EXPANDED(收录号:WOS:000384038400040)】；

基金：This work was jointly supported by the National Natural Science Foundation of China (Grants 21335003, 21575089, 21675052), the Key Grant Project of Chinese Ministry of Education (Grant 313019), and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：DNA - Nanoclusters - Silver compounds - Probes - Alkalinity - Chemical modification - Fluorescence - Phosphatases - Silver

摘要：We present a new copper-mediated on-off switch for detecting either pyrophosphate (PPi) or alkaline phosphatase (ALP) based on DNA-scaffolded silver nano-clusters (DNA/AgNCs) templated by a single-stranded sequence containing a 15-nt polythymine spacer between two different emitters. The switch is based on three favorable properties: the quenching ability of Cu2+ for DNA/AgNCs with excitation at 550 nm; the strong binding capacity of Cr2+ and PPi; and the ability of ALP to, transform PPi into orthophosphate (Pi). The change id, fluorescence of DNA/AgNCs depends on the concentrations, of Cu2+, PPi, and ALP. Copper(II). acts as a mediator to interact,specifically with the Probe, while PPi :and ALP convert the signal of the Probe by removing and recovering Cu2+, operating as an on-off switch: In the presence of Cu2+ only, DNA/AgNCs exhibit low fluorescence because the combination of,Cu2+ and DNA template disturbs the precise formation of DNA/AgNCs. When PPi is added to the system. containing Cu2+, free DNA template is obtained due to the stronger interaction of PPi and Cu2+, leading to a significant fluorescence increase (ON state) which depends on the concentration of PPi. Further addition of ALP results in the release of free Cu2+ via ALP-catalysis of hydrolysis of PPi into Pi, thereby-returning the system to,the low fluorescence OFF state. The switch allows the analysis of either PPi or ALP by observation-of the fluorescence status, with the detection limit of 112.69 nM and 0.005 U/mL for PPi. and ALP, respectively. The AgNCs on-off switch provides the advantages of simple design, convenient operation, and low experimental cost without need of chemical modification, organic dyes, or separation procedures.