title: Electrochemical biosensor for Ni(2+) detection based on a DNAzyme-CdSe nanocomposite.
abstract: The detection and speciation analysis of metal-ion is very important for environmental monitoring. A novel electrochemical biosensor for Nickel(II) detection based on a DNAzyme-CdSe nanocomposite was developed. We firstly hybridized with capture probe (DNA1) and sequentially with DNA (DNA2) on the gold electrode. Then CdSe QDs were incorporated the specific recognition of DNA2 by covalent assembling. Upon addition of nickel ion into the above system, the substrate strand of the immobilized DNAzyme was catalytically cleaved by target Ni(2+), resulting in disassociation of the shorter DNA fragments containing CdSe QDs. The remaining CdSe QDs on the electrode surface detected by differential pulse anodic stripping voltammetry (DPASV). Under optimal conditions, the as-prepared sensor exhibited high sensitivity and fast response to Ni(2+) with the linear range from 20 nM to 0.2mM and a low detection limit of 6.67 nM. The prepared biosensor also shows good stability and good reproducibility and high selectivity toward target Ni(2+) against other metal ions because of highly specific Ni(2+)-dependent DNAzyme. Thus, our strategy has a good potential in the environment surveys.
authors.affiliation: School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yang
authors.affiliation: School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, PR China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, PR China.
authors.forename: Xing-Pei
authors.initials: XP
authors.lastname: Liu
authors.affiliation: School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, PR China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Liu
authors.affiliation: School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, PR China. Electronic address: maochangjie@sina.com.
authors.forename: Chang-Jie
authors.initials: CJ
authors.lastname: Mao
authors.affiliation: School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, PR China.
authors.forename: He-Lin
authors.initials: HL
authors.lastname: Niu
authors.affiliation: School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, PR China.
authors.forename: Bao-Kang
authors.initials: BK
authors.lastname: Jin
authors.affiliation: School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, PR China.
authors.forename: Sheng-Yi
authors.initials: SY
authors.lastname: Zhang
mesh_terms: D015374:Biosensing Techniques; D019187:Cadmium Compounds / Q000737:chemistry*; D003217:Conductometry / Q000295:instrumentation*; D021881:DNA, Catalytic / Q000737:chemistry*; D004784:Environmental Monitoring / Q000295:instrumentation; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D009532:Nickel / Q000032:analysis* / Q000737:chemistry; D018036:Selenium Compounds / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019187:Cadmium Compounds; D021881:DNA, Catalytic; D004800:Enzymes, Immobilized; D018036:Selenium Compounds; D014874:Water Pollutants, Chemical; D009532:Nickel; C058667:cadmium selenide
keywords: DNAzyme-CdSe nanocomposite; Electrochemical biosensor; Nickel