title: Electrochemical DNA biosensor for screening of chlorinated benzene pollutants.
abstract: In this work, an electrochemical DNA biosensor based on double-stranded DNA modified Au electrode (dsDNA/Au) was proposed for the rapid screening and detection of chlorinated benzenes pollutants, in which redox-active methylene blue (MB) was used to amplify the interaction between dsDNA and the target analyte. Using hexachlorobenzene (HCB) as a model analyte of chlorinated benzenes, the biosensor demonstrated a linear response with the logarithm of HCB concentrations from 100 pmol L(-1) to 100 nmol L(-1). The obtained detection limit was 30 pmol L(-1), which was remarkably superior to other biosensors. The interaction mechanism of the biosensor with HCB was proposed based on systematical characterization by cyclic voltammetry (CV), differential pulse voltammetry (DPV), UV-vis spectrometry and electrochemical quartz crystal microbalance (EQCM). Further studies revealed that the biosensor could screen chlorinated benzenes in the presence of 100 fold amount of other co-existing chemicals (ethyl acetate and sodium oxalate, etc.), and the response signal of the biosensors for different chlorinated benzenes was correlative to their respective toxicity. The proposed biosensor proved to be a promising "alarm" tool for rapid screening of chlorinated benzenes in real water samples.
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
authors.forename: Lidong
authors.initials: L
authors.lastname: Wu
authors.forename: Xianbo
authors.initials: X
authors.lastname: Lu
authors.forename: Jing
authors.initials: J
authors.lastname: Jin
authors.forename: Haijun
authors.initials: H
authors.lastname: Zhang
authors.forename: Jiping
authors.initials: J
authors.lastname: Chen
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002722:Chlorobenzenes / Q000032:analysis*; D015342:DNA Probes; D055664:Electrochemical Techniques; D006581:Hexachlorobenzene / Q000032:analysis; D008751:Methylene Blue; D010084:Oxidation-Reduction; D058525:Quartz Crystal Microbalance Techniques; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002722:Chlorobenzenes; D015342:DNA Probes; D014874:Water Pollutants, Chemical; D006581:Hexachlorobenzene; D008751:Methylene Blue