Enzyme-free nucleic acid dual-amplification strategy combined with mimic enzyme catalytic precipitation reaction for the photoelectrochemical detection of microRNA-21

• Published in: Mikrochimica acta (1966) 2022-07, Vol.189 (7), p.249-249, Article 249
• Main Authors: Zhao, Yan, Li, Xiaomeng, Xiang, Mei-Hao, Gao, Feng, Qu, Fengli, Li, Mingfang, Lu, Limin
• Format: Article
• Language: English
• Subjects: Acids; Amplification; Analytical Chemistry; Aqueous solution reactions; Biosensors; Characterization and Evaluation of Materials; Chemical precipitation; Chemistry; Chemistry and Materials Science; Detectors; Electrodes; Entropy of reaction; Enzymes; Manganese; Microengineering; MicroRNA; MicroRNAs; Nanochemistry; Nanotechnology; Nucleic acids; Original Paper; Peroxidase; Photoelectric effect; Photosensitivity; Porphyrins; Ribonucleic acid; RNA; Synergistic effect
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-022-05345-y

A novel photoelectrochemical (PEC) biosensor based on an enzyme-free nucleic acid dual-amplification strategy combined with a mimic enzyme to catalyze the deposition of a quencher is reported for the ultrasensitive detection of miRNA-21. A limited amount of target miRNA-21 can trigger the formation of long DNA duplexes on the electrode, owing to the synergistic effect of the enzyme-free nucleic acid dual-amplification strategy of entropy-driven strand displacement reaction (ESDR) amplification and hybridization chain reaction (HCR) amplification. The embedded manganese porphyrin (MnPP) in the long DNA duplexes acts as a horseradish peroxidase (HRP)–mimicking enzyme to catalyze the transformation of benzo-4-chlorohexadienone on the electrode surface, resulting in a significant reduction in photocurrent intensity. As a photosensitive material, BiOCl-BiOI is used as a tag to provide strong initial PEC signals. Based on the cascade integration of the enzyme-free nucleic acid dual-amplification strategy and the mimic enzyme-catalyzed precipitation reaction, the current PEC biosensor exhibits outstanding performance for miRNA-21 detection with an ultralow detection limit (33 aM) and a wide quantification range (from 100 aM to 1 nM). This work provides a new avenue toward the ultrasensitive detection of miRNAs, and is expected to be used for clinical and biochemical samples. Graphical abstract A unique PEC biosensor with the BiOCl-BiOI composite, as the photosensitive material, has been developed for ultrasensitive miRNA-21 determination based on the combination of an enzyme-free nucleic acid dual-amplification strategy and mimic enzyme catalytic precipitation reaction.