title: A Fluorescence Sensor for Lead (II) Ions Determination Based on Label-Free Gold Nanoparticles (GNPs)-DNAzyme Using Time-Gated Mode in Aqueous Solution.
abstract: This paper describes a label-free 17E DNAzyme-based time-gated fluorescence sensor for Pb2+detection by unmodified gold nanoparticles (GNPs) and a terbium ternary complex. The fluorophore that used in this paper is a terbium ternary complex. Its signal can be measured in a time-gated manner which could eliminate most of the unspecific fluorescent background. It is well known that unfolded single-stranded DNA (ssDNA) could be adsorbed on GNPs while double-stranded DNA could not. The cleavage of the substrate by the 17E DNAzyme in the presence of Pb2+causes the release of ssDNA from the 17E-17S duplex to be absorbed onto GNPs, preventing the aggregation of GNPs and then leading to a fluorescence decrease of terbium ternary complex. By means of this method, the authors have successfully detected Pb2+over a range of 10 nM to 2500 nM with a detection limit of 1.7 nM. The sensor also exhibited good selectivity. The sensor provided a simple, cost-effective, rapid and sensitive measurement tool for Pb2+detection.
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Hunan University, Changsha, 410082, China.|College of Chemistry and Chemical Engineering, Xinxiang University, Xinxiang, 453003, China.
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Wang
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Hunan University, Changsha, 410082, China. cgniu@hnu.edu.cn.
authors.forename: Cheng-Gang
authors.initials: CG
authors.lastname: Niu
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Hunan University, Changsha, 410082, China.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Guo
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Hunan University, Changsha, 410082, China.
authors.forename: Liu-Yin
authors.initials: LY
authors.lastname: Hu
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Hunan University, Changsha, 410082, China.
authors.forename: Sheng-Quan
authors.initials: SQ
authors.lastname: Wu
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Hunan University, Changsha, 410082, China.
authors.forename: Guang-Ming
authors.initials: GM
authors.lastname: Zeng
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Hunan University, Changsha, 410082, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Li
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D021881:DNA, Catalytic / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D007854:Lead / Q000032:analysis*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*
chemical_list: D021881:DNA, Catalytic; D005456:Fluorescent Dyes; D007854:Lead; D006046:Gold
keywords: DNAzyme; Gold nanoparticles; Terbium ternary complex; Time-gated fluorescence