title: Practical, highly sensitive, and regenerable evanescent-wave biosensor for detection of Hg(2+) and Pb(2+) in water.
abstract: A "turn-on" evanescent-wave fiber biosensor based on functional nucleic acids was developed for on-site detection of Hg(2+) and Pb(2+) in environmental water samples. A two-step strategy was conducted to take advantage of the rapid binding of T-T mismatches with Hg(2+) and the cleavage of a substrate by 8-17 DNAzyme with Pb(2+) in solution, as well as sensitive DNA detection on a liquid-solid interface based on evanescent wave. The biosensor demonstrated high sensitivity (with a detection limit of 22 pM for Hg(2+) and 20 nM for Pb(2+)) and selectivity without any signal amplification, rapid detection (within 13 min per test), low cost (10-20 Chinese yuan per sample), and multiple-cycle regeneration (at least 18 times). The method was also successfully applied on Hg(2+) and Pb(2+) detection in real environmental water samples.
authors: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Shitong
authors: S
authors: Han
authors: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Xiaohong
authors: X
authors: Zhou
authors: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Yunfei
authors: Y
authors: Tang
authors: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: hemiao@mail.tsinghua.edu.cn.
authors: Miao
authors: M
authors: He
authors: Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors: Xinyu
authors: X
authors: Zhang
authors: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Hanchang
authors: H
authors: Shi
authors: Department of Chemistry, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, China.
authors: Yu
authors: Y
authors: Xiang
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry; D021881:DNA, Catalytic / Q000737:chemistry; D004784:Environmental Monitoring; D007854:Lead / Q000737:chemistry / Q000302:isolation & purification*; D057230:Limit of Detection; D008628:Mercury / Q000737:chemistry / Q000302:isolation & purification*; D055100:Optical Fibers
chemical_list: D021881:DNA, Catalytic; D007854:Lead; D004247:DNA; D008628:Mercury
keywords: Fluorescent biosensor; Functional nucleic acids; Heavy metal ions; On-site; Regeneration