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Highly Selective and Sensitive microRNA-210 Assay Based on Dual-Signaling Electrochemical and Photocurrent-Polarity-Switching Strategies

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journal contribution
posted on 14.10.2021, 04:04 by Qingqing Zhang, Suying Liu, Cuicui Du, Yamin Fu, Ke Xiao, Xiaohua Zhang, Jinhua Chen
Highly sensitive and selective microRNA (miRNA) assay is of great significance for disease diagnosis and therapy. Herein, a magnetic-assisted electrochemistry (EC)–photoelectrochemistry (PEC) dual-mode biosensing platform was developed for miRNA-210 detection based on dual-signaling EC and photocurrent-polarity-switching PEC strategies. Porous magnetic Fe3O4 octahedra with a large surface area were synthesized by calcining Fe-based metal–organic frameworks. Subsequently, the magnetic photoelectric materials (Fe3O4@CdS) were developed by the successive ionic layer adsorption and reaction method in Cd2+ and S2– solutions. Then, the self-assembled DNA nanoprisms contained three thiols/hanging arms that could capture miRNA-210 efficiently and were anchored to the Fe3O4@CdS octahedra via the Cd–S bond. When miRNA-210 was present, the double-stranded DNA concatemers [the self-assembled duplex helixes based on a pair of methylene blue (MB)-labeled single-stranded DNAs (AP1 and AP2) through the hybridization chain reaction and then intercalated with adriamycin (Dox) into their grooves] were connected with the Fe3O4@CdS-DNA nanoprisms. MB and Dox not only acted as the electrochemical probes but also synergistically switched the photocurrent polarity of the Fe3O4@CdS octahedra. Thus, miRNA-210 was assayed sensitively and selectively via the proposed EC–PEC dual-mode biosensing platform. Additionally, the abovementioned recognition steps occurred in a homogeneous system, and the effects of the impurities and interferences on the miRNA-210 assay could be easily avoided by magnetic separation due to the good magnetic properties of Fe3O4 octahedra. The proposed EC–PEC dual-mode biosensing platform showed a wide range of potential applications in bioanalysis and early diagnosis of disease.

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