Au nanoparticles/hollow molybdenum disulfide microcubes based biosensor for microRNA-21 detection coupled with duplex-specific nuclease and enzyme signal amplification.
An ultrasensitive electrochemical biosensor for detecting microRNAs is fabricated based on hollow molybdenum disulfide (MoS2) microcubes. Duplex-specific nuclease, enzyme and electrochemical-chemical-chemical redox cycling are used for signal amplification. Hollow MoS2microcubes constructed by ultrathin nanosheets are synthesized by a facile template-assisted strategy and used as supporting substrate. For biosensor assembling, biotinylated ssDNA capture probes are first immobilized on Au nanoparticles (AuNPs)/MoS2modified electrode in order to combine with streptavidin-conjugated alkaline phosphatase (SA-ALP). When capture probes hybridize with miRNAs, duplex-specific nuclease cleaves the formative duplexes. At the moment, the biotin group strips from the electrode surface and SA-ALP is incapacitated to attach onto electrode. Then, ascorbic acids induce the electrochemical-chemical-chemical redox cycling to produce electrochemical response in the presence of ferrocene methanol and tris (2-carboxyethyl) phosphine. Under optimum conditions, the proposed biosensor shows a good linear relationship between the current variation and logarithm of the microRNAs concentration ranging from 0.1fM to 0.1pM with a detection limit of 0.086fM (S/N=3). Furthermore, the biosensor is successfully applied to detect target miRNA-21 in human serum samples.
College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
Hong-Lei
HL
Shuai
College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China; Institute for Conservation and Utilization of Agro-bioresources in Dabie Mountains, Xinyang Normal University, Xinyang 464000, China. Electronic address: kejinghuang11@163.com.
Ke-Jing
KJ
Huang
College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
Ying-Xu
YX
Chen
College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
Lin-Xia
LX
Fang
College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
Meng-Pei
MP
Jia
D015374:Biosensing Techniques; D001710:Biotin / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D035683:MicroRNAs / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification*; D008982:Molybdenum / Q000737:chemistry
D004277:DNA, Single-Stranded; D004220:Disulfides; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D001710:Biotin; D006046:Gold; D008982:Molybdenum; C082964:molybdenum disulfide
Duplex-specific nuclease; Electrochemical biosensor; Enzyme signal amplification; Hollow molybdenum disulfide microcubes; MicroRNAs