title: An electrochemical aptamer biosensor based on "gate-controlled" effect using β-cyclodextrin for ultra-sensitive detection of trace mercury.
abstract: A new strategy for construction an electrochemical biosensor for Hg(2+) analysis with extremely high sensitivity was proposed based on "T-Hg(2+)-T" coordination by aptamers and "gate-controlled" amplification by switch of the channels of the probe. SH-β-cyclodextrin was self-assembled on the gold electrode to form an orderly arranged molecularly layer with interspaces among β-CDs; thionine labeled aptamer was then linked on the assembled β-CD. When Hg(2+) was added, the aptamer combined with Hg(2+) and formed "T-Hg(2+)-T" structure, which caused the aptamer folded and the labeled thionine covered the interspaces to block off the channel for probe entrance. The oxidative current of probe decreased, which provide the basis for the determination of Hg(2+). With the gate-controlled amplification, the changes of trace amounts of Hg(2+) will produce great changes of the probe current. The sensor exhibited significantly higher sensitivity with a detection limit of 5.0×10(-15) mol/L, which is lower than other reported methods.
authors.affiliation: Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, China. Electronic address: likianping@263.net.
authors.forename: Jianping
authors.initials: J
authors.lastname: Li
authors.affiliation: Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, China.
authors.forename: Mi
authors.initials: M
authors.lastname: Sun
authors.affiliation: Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Wei
authors.affiliation: Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, China.
authors.forename: Lieping
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000235:genetics; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008628:Mercury / Q000032:analysis*; D008832:Microchemistry / Q000295:instrumentation*; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis*; D047392:beta-Cyclodextrins / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D014874:Water Pollutants, Chemical; D047392:beta-Cyclodextrins; D008628:Mercury; C031215:betadex
keywords: Aptamer; Biosensor; Gate-controlled; Hg(2+); β-cyclodextrin