title: A novel electrochemical biosensor for ultrasensitive and specific detection of DNA based on molecular beacon mediated circular strand displacement and rolling circle amplification.
abstract: A novel electrochemical biosensing strategy was developed for ultrasensitive and specific detection of target DNA using a cascade signal amplification based on molecular beacon (MB) mediated circular strand displacement (CSD), rolling circle amplification (RCA), biotin-strepavidin system, and enzymatic amplification. The target DNA hybridized with the loop portion of MB probe immobilized on the gold electrode and triggered the CSD, leading to multiple biotin-tagged DNA duplex. Furthermore, via biotin-streptavidin interaction, the RCA was implemented, producing long massive tandem-repeat DNA sequences for binding numerous biotinylated detection probes. This enabled an ultrasensitive electrochemical readout by further employing the streptavidin-alkaline phosphatase. The proposed biosensor showed very high sensitivity and selectivity with a dynamic response range from 1 fM to 100 pM. The proposed strategy could have the potential for applying in clinical molecular diagnostics and environmental monitoring.
authors.affiliation: The Center for Clinical Molecular Medical detection, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics, Ministry of Education, College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics, Ministry of Education, College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Yurong
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics, Ministry of Education, College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Shen
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics, Ministry of Education, College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics, Ministry of Education, College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Pinhua
authors.initials: P
authors.lastname: Lei
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics, Ministry of Education, College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China. Electronic address: dingshijia@163.com.
authors.forename: Shijia
authors.initials: S
authors.lastname: Ding
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D001710:Biotin; D004247:DNA / Q000032:analysis* / Q000235:genetics; D058266:Dielectric Spectroscopy; D055664:Electrochemical Techniques; D004784:Environmental Monitoring; D006801:Humans; D025202:Molecular Diagnostic Techniques; D021141:Nucleic Acid Amplification Techniques; D009693:Nucleic Acid Hybridization; D015203:Reproducibility of Results; D019809:Streptavidin
chemical_list: D001710:Biotin; D004247:DNA; D019809:Streptavidin
keywords: Alkaline phosphatase; Circular isothermal strand displacement amplification; Electrochemical DNA sensor; Rolling circle amplification