title: An electrochemical biosensor for sensitive detection of microRNA-155: combining target recycling with cascade catalysis for signal amplification.
abstract: In this work, a new electrochemical biosensor based on catalyzed hairpin assembly target recycling and cascade electrocatalysis (cytochrome c (Cyt c) and alcohol oxidase (AOx)) for signal amplification was constructed for highly sensitive detection of microRNA (miRNA). It is worth pointing out that target recycling was achieved only based on strand displacement process without the help of nuclease. Moreover, porous TiO2 nanosphere was synthesized, which could offer more surface area for Pt nanoparticles (PtNPs) enwrapping and enhance the amount of immobilized DNA strand 1 (S1) and Cyt c accordingly. With the mimicking sandwich-type reaction, the cascade catalysis amplification strategy was carried out by AOx catalyzing ethanol to acetaldehyde with the concomitant formation of high concentration of H2O2, which was further electrocatalyzed by PtNPs and Cyt c. This newly designed biosensor provided a sensitive detection of miRNA-155 from 0.8 fM to 1 nM with a relatively low detection limit of 0.35 fM.
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, P. R. China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Wu
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.forename: Pu
authors.initials: P
authors.lastname: Zhang
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
mesh_terms: D000079:Acetaldehyde / Q000737:chemistry; D000429:Alcohol Oxidoreductases / Q000737:chemistry; D052157:Aptamers, Nucleotide / Q000737:chemistry; D001483:Base Sequence; D001672:Biocompatible Materials / Q000737:chemistry; D015374:Biosensing Techniques; D002384:Catalysis; D019343:Citric Acid / Q000737:chemistry; D045304:Cytochromes c / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D053758:Nanoparticles / Q000737:chemistry; D010084:Oxidation-Reduction; D016062:Porosity; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D014025:Titanium / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D001672:Biocompatible Materials; C524942:MIRN155 microRNA, human; D035683:MicroRNAs; C009495:titanium dioxide; D019343:Citric Acid; D045304:Cytochromes c; D006861:Hydrogen Peroxide; D014025:Titanium; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D000079:Acetaldehyde
keywords: cascade catalysis; dual signal amplification; microRNA; target catalyzed hairpin assembly