title: A label-free fluorescent biosensor for ultratrace detection of terbium (ш) based on structural conversion of G-quadruplex DNA mediated by ThT and terbium (ш).
abstract: In this paper, a novel label-free fluorescent biosensor for terbium (ш) (Tb(3+)) was proposed based on structural conversion of G-quadruplex DNA mediated by Thioflavin T (ThT) and Tb(3+). In the presence of K(+), ThT could bind to K(+)-stabilized parallel G-quadruplex, giving rise to high fluorescence intensity. Upon the addition of Tb(3+), Tb(3+) could competitively bind to parallel G-quadruplex leading to the structural change, which resulted in fluorescence decrease. The change of fluorescence intensity (ΔF=F0-F) showed a good linear response toward the concentration of Tb(3+) over the range from 1.0 pM to 10.0 µM with a limit of detection of 0.55 pM. This proposed biosensor was simple and cost-effective in design and in operation with ultrahigh sensitivity and selectivity. Thus, the proposed biosensor could be a promising candidate for monitoring ultratrace Tb(3+) in environment.
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, China; Environmental Monitoring Center of Fujian Province, Fuzhou, Fujian 350003, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, China.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Zuo
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, China.
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Chen
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Tong
authors.affiliation: Environmental Monitoring Center of Fujian Province, Fuzhou, Fujian 350003, China.
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Mo
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, China. Electronic address: zlan@fzu.edu.cn.
authors.forename: Lan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Food Safety Key laboratory of Zhejiang Province, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310035, China; Food Safety Key Laboratory of Liaoning Province, Bohai University, Jinzhou 121013, China. Electronic address: lijr6491@yahoo.com.cn.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Li
mesh_terms: D052160:Benzothiazoles; D015374:Biosensing Techniques / Q000379:methods*; D002412:Cations / Q000032:analysis; D004247:DNA / Q000737:chemistry*; D004784:Environmental Monitoring / Q000379:methods; D005456:Fluorescent Dyes; D054856:G-Quadruplexes; D057230:Limit of Detection; D045483:Rivers / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013725:Terbium / Q000032:analysis*; D013844:Thiazoles / Q000737:chemistry*
chemical_list: D052160:Benzothiazoles; D002412:Cations; D005456:Fluorescent Dyes; D013844:Thiazoles; D013725:Terbium; C009462:thioflavin T; D004247:DNA
keywords: Fluorescent biosensor; G-quadruplex; Terbium (ш); Thioflavin T