title: Bi-directional DNA Walking Machine and Its Application in an Enzyme-Free Electrochemiluminescence Biosensor for Sensitive Detection of MicroRNAs.
abstract: Herein, a dual microRNA (miRNA) powered bi-directional DNA walking machine with precise control was developed to fabricate an enzyme-free biosensor on the basis of distance-based electrochemiluminescence (ECL) energy transfer for multiple detection of miRNAs. By using miRNA-21 as the driving force, the DNA walker could move forth along the track and generated quenching of ECL response due to the proximity between Au nanoparticles (AuNPs) and Mn2+doped CdS nanocrystals (CdS:Mn NCs) film as the ECL emitters, realizing ultrasensitive determination of miRNA-21. Impressively, once miRNA-155 was introduced as the driving force, the walker could move back along the track automatically, and surface plasmon resonance (SPR) occurred owing to the appropriate large separation between AuNPs and CdS:Mn NCs, achieving an ECL enhancement and realizing ultrasensitive detection of miRNA-155. The bi-directional movement of the DNA walker on the track led to continuous distance-based energy transfer from CdS:Mn NCs film by AuNPs, which resulted in significant ECL signal variation of CdS:Mn NCs for multiple detection of miRNA-21 and miRNA-155 down to 1.51 fM and 1.67 fM, respectively. Amazingly, the elaborated biosensor provided a new chance for constructing controllable molecular nanomachines in biosensing, disease diagnosis, and clinical analysis.
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, People's Republic of China.
authors.forename: Lichun
authors.initials: L
authors.lastname: Peng
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, People's Republic of China.
authors.forename: Pu
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, People's Republic of China.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, People's Republic of China.
authors.forename: Ruo
authors.identifier: 0000-0003-3664-6236
authors.initials: R
authors.lastname: Yuan
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D055664:Electrochemical Techniques / Q000379:methods; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000379:methods; D053768:Metal Nanoparticles / Q000737:chemistry; D035683:MicroRNAs / Q000032:analysis* / Q000235:genetics; D036103:Nanotechnology / Q000295:instrumentation*; D009693:Nucleic Acid Hybridization; D015203:Reproducibility of Results
chemical_list: D035683:MicroRNAs; D004247:DNA