title: Amplified electrochemical detection of nucleic acid hybridization via selective preconcentration of unmodified gold nanoparticles.
abstract: The common drawback of optical methods for rapid detection of nucleic acid by exploiting the differential affinity of single-/double-stranded nucleic acids for unmodified gold nanoparticles (AuNPs) is its relatively low sensitivity. In this article, on the basis of selective preconcentration of AuNPs unprotected by single-stranded DNA (ssDNA) binding, a novel electrochemical strategy for nucleic acid sequence identification assay has been developed. Through detecting the redox signal mediated by AuNPs on 1, 6-hexanedithiol blocked gold electrode, the proposed method is able to ensure substantial signal amplification and a low background current. This strategy is demonstrated for quantitative analysis of the target microRNA (let-7a) in human breast adenocarcinoma cells, and a detection limit of 16 fM is readily achieved with desirable specificity and sensitivity. These results indicate that the selective preconcentration of AuNPs for electrochemical signal readout can offer a promising platform for the detection of specific nucleic acid sequence.
authors: Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
authors: Yuan
authors: Y
authors: Li
authors: Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
authors: Rui
authors: R
authors: Tian
authors: Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China. Electronic address: zhengxw@snnu.edu.cn.
authors: Xingwang
authors: X
authors: Zheng
authors: College of Materials, Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China. Electronic address: huangrongfu13@cdut.cn.
authors: Rongfu
authors: R
authors: Huang
mesh_terms: D015374:Biosensing Techniques; D001943:Breast Neoplasms / Q000737:chemistry* / Q000473:pathology; D055664:Electrochemical Techniques; D004566:Electrodes; D005260:Female; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D035683:MicroRNAs / Q000032:analysis*; D009693:Nucleic Acid Hybridization; D012680:Sensitivity and Specificity
chemical_list: D035683:MicroRNAs; D006046:Gold
keywords: DNA probe; Electrochemical method; MicroRNA; Preconcentration effect; Unmodified gold nanoparticle