A SERS/fluorescence dual-mode nanosensor based on the human telomeric G-quadruplex DNA: Application to mercury (II) detection.
DNA-metal nanoparticle conjugates have been increasingly exploited for sensing purposes over the past decades. However, most of the existing strategies are operated with canonical DNA structures, such as single-stranded forms, stem-loop structures, and double helix structures. There is intense interest in the development of nano-system based on high order DNA secondary structures. Herein, we propose a SERS/fluorescence dual-mode nanosensor, where the signal transduction mechanism is based on the conformational switching of the human telomeric G-quadruplex DNA. The nanosensor exhibits excellent SERS/fluorescence responses to the complementary strands of G-quadruplexes. Based on T-Hg(2+)-T coordination chemistry, this sensor is effectively applied to determination of Hg(2+) in buffer solution and real samples. It achieves a limit of detection (LOD) as low as 1ppt, which is ~100 times more sensitive than conventional optical sensors. We anticipate that the proposed G-quadruplex-based nanosensor could be applied to the analysis of other metal ions and small molecules in environmental samples and biological systems.
College of Science, China Three Gorges University, Yichang 443002, Hubei, China; Advanced Photonics Center, Southeast University, 2# Sipai Lou, Nanjing 210096, Jiangsu, China. Electronic address: lmin@ctgu.edu.cn.
Min
M
Liu
Advanced Photonics Center, Southeast University, 2# Sipai Lou, Nanjing 210096, Jiangsu, China.
Zhuyuan
Z
Wang
College of Science, China Three Gorges University, Yichang 443002, Hubei, China.
Liqing
L
Pan
Advanced Photonics Center, Southeast University, 2# Sipai Lou, Nanjing 210096, Jiangsu, China.
Yiping
Y
Cui
College of Science, China Three Gorges University, Yichang 443002, Hubei, China. Electronic address: lym@ctgu.edu.cn.
Yiman
Y
Liu
D004247:DNA / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D054856:G-Quadruplexes; D006801:Humans; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D058726:Nanoconjugates / Q000737:chemistry / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*; D016615:Telomere / Q000737:chemistry* / Q000235:genetics; D014874:Water Pollutants, Chemical / Q000032:analysis
D058726:Nanoconjugates; D014874:Water Pollutants, Chemical; D004247:DNA; D008628:Mercury
Ag@Au nanoparticles; Human telomeric G-quadruplex DNA; SERS