title: Enhanced electrochemical recognition of double-stranded DNA by using hybridization chain reaction and positively charged gold nanoparticles.
abstract: Enhanced sequence-specific recognition of double-stranded DNA (dsDNA) was realized by using hybridization chain reaction (HCR) and positively charged gold nanoparticles ((+)AuNPs) dual signal amplification. To construct such a sensor, capture probe was initially assembled onto gold electrode surface. Upon addition of dsDNA, sandwiched DNA complex was formed between the capture probe and the detection probe, then another exposed part of the detection probe opened two alternating DNA hairpins (H1 and H2) in turn and initiated HCR to form a double-helix. Meantime, (+)AuNPs were electrostatically adsorbed onto such double-helix to amplify the electrochemical signal. Upon optimal conditions, the electronic signals of ferrocene (Fc) that modified on H1 and H2 increased linearly with increasing dsDNA concentration over the range from 15 pM to 1.0 nM, with a detection limit of 2.6 pM. Moreover, the proposed method showed good sequence specificity for dsDNA recognition.
authors.affiliation: School of Life Science, Jiangsu Normal University, Xuzhou 221116, PR China.
authors.forename: Zongbing
authors.initials: Z
authors.lastname: Li
authors.affiliation: School of Life Science, Jiangsu Normal University, Xuzhou 221116, PR China. Electronic address: mxm0107@jsnu.edu.cn.
authors.forename: Xiangmin
authors.initials: X
authors.lastname: Miao
authors.affiliation: School of Life Science, Jiangsu Normal University, Xuzhou 221116, PR China.
authors.forename: Ke
authors.initials: K
authors.lastname: Xing
authors.affiliation: School of Life Science, Jiangsu Normal University, Xuzhou 221116, PR China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Zhu
authors.affiliation: School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, PR China. Electronic address: cesllsh@mail.sysu.edu.cn.
authors.forename: Liansheng
authors.initials: L
authors.lastname: Ling
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000295:instrumentation; D003217:Conductometry / Q000295:instrumentation*; D004247:DNA / Q000032:analysis / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D017403:In Situ Hybridization / Q000295:instrumentation*; D008969:Molecular Sequence Data; D053758:Nanoparticles / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000295:instrumentation*; D055672:Static Electricity
chemical_list: D006046:Gold; D004247:DNA
keywords: Double-stranded DNA; Electrochemical sensor; Hybridization chain reaction; Positively charged gold nanoparticles