A highly sensitive label-free sensor for Mercury ion (Hg²⁺) by inhibiting thioflavin T as DNA G-quadruplexes fluorescent inducer.
DNA sequences with guanine repeats can be induced to form G-quartets that adopt G-quadruplex structures in the presence of thioflavin T (ThT). ThT plays a dual role of inducing DNA sequences to fold into quadruplex structures and of sensing the change by its remarkable fluorescence enhancement. ThT binding to the DNA sequences with guanine repeats showed highly specific fluorescence enhancement compared with single/double-stranded DNA. In this work, we have utilized the conformational switch from G-quadruplex complex induced by fluorogenic dye ThT to Hg(2+) mediated T-Hg-T double-stranded DNA formation, thereby pioneering a facile approach to detect Hg(2+) with fluorescence spectrometry. Through this approach, Hg(2+) in aqueous solutions can be detected at 5 nM with fluorescence spectrometry in a facile way, with high selectivity against other metal ions. These results indicate the introduced label-free method for fluorescence spectrometric Hg(2+) detection is simple, quantitative, sensitive, and highly selective.
State Key Laboratory for Chemo/biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
Jia
J
Ge
State Key Laboratory for Chemo/biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
Xi-Ping
XP
Li
State Key Laboratory for Chemo/biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
Jian-Hui
JH
Jiang
State Key Laboratory for Chemo/biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China. Electronic address: rqyu@hnu.edu.cn.
Ru-Qin
RQ
Yu
D052160:Benzothiazoles; D015374:Biosensing Techniques / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D054856:G-Quadruplexes; D008628:Mercury / Q000032:analysis* / Q000378:metabolism; D013050:Spectrometry, Fluorescence / Q000379:methods; D013844:Thiazoles / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism
D052160:Benzothiazoles; D005456:Fluorescent Dyes; D013844:Thiazoles; D014874:Water Pollutants, Chemical; C009462:thioflavin T; D008628:Mercury
DNA G-quadruplex; Fluorescence inducer; Label-free; Mercury ion; Thioflavin T