title: A novel electrochemiluminescence biosensor for the detection of microRNAs based on a DNA functionalized nitrogen doped carbon quantum dots as signal enhancers.
abstract: An ultrasensitive electrochemiluminescence (ECL) biosensor for the detection of microRNA was developed based on nicking enzymes Nb.BbvCI mediated signal amplification (NESA). First, the hairpin probe1-N-CQDs with assistant probe and microRNA (miRNA) formed Y junction structure which was cleaved with the addition of nicking enzymes Nb.BbvCI to release miRNA and assistant probe. Subsequently, the released miRNA and assistant probe can initiate the next recycling process. The generation of numerous intermediate sequences nitrogen doped carbon quantum dots-DNA (N-CQDs-DNA) can further hybridize with hairpin probe2 immobilized on GO/Au composite modified electrode surface, the initial ECL intensity was enhanced. The ECL intensity would increase with increasing concentration of the target miRNA, and the sensitivity of biosensor would be promoted because of the efficient signal amplification of the target induced cycling reaction. The novel designed biosensor provided a highly sensitive and selective detection of miRNA-21 from 10 aM to104fM with a relatively low detection limit of 10 aM. Thus, our strategy has a potential application in the clinical diagnosis.
authors.affiliation: School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, PR China; State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry& Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry& Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Ma
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: Yu-Pin
authors.initials: YP
authors.lastname: Wei
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: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry& Chemical Engineering, Nanjing University, Nanjing 210093, PR China. Electronic address: jjzhu@nju.edu.cn.
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Zhu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods; D006801:Humans; D061925:Immobilized Nucleic Acids / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods; D035683:MicroRNAs / Q000032:analysis*; D009584:Nitrogen / Q000737:chemistry; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D009693:Nucleic Acid Hybridization / Q000379:methods; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D061925:Immobilized Nucleic Acids; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D002244:Carbon; D009584:Nitrogen
keywords: Electrochemiluminescence biosensor; Nicking enzymes; Nitrogen doped carbon quantum dots; Signal amplification; miRNA-21