Engineering entropy-driven based multiple signal amplification strategy for visualized assay of miRNA by naked eye

• Published in: Talanta (Oxford) 2021-12, Vol.235, p.122810-122810, Article 122810
• Main Authors: Zhu, Sha, Yang, Yi qi, Ding, Yuedi, Feng, Ninghan, Li, Menglu, Yin, Yongmei
• Format: Article
• Language: English
• Subjects: Colorimetric biosensor; Entropy-driven; Gold nanoparticle; MicroRNA detection; Multiple signal amplification; Nicking enzyme
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2021.122810

MicroRNAs (miRNAs) are currently recognized as novel biomarkers for cancer early diagnosis, therapy selection, and progression monitoring. Herein, we developed an ultrasensitive and label-free homogeneous colorimetric strategy for miRNA detection based on engineering entropy-driven amplification (EDA) coupled with nicking enzyme-assisted AuNP aggregation. In our design, the target miRNA could specifically trigger the EDA recycling process. One of the EDA products could open the hairpin probe and form a dual strand containing a nicking endonuclease (Nb.BbvCl) cleavage region. After adding nicking endonuclease in the sensing solution, the product DNA fragments could act as two linkers, inducing the aggregation of ssDNA-modified AuNPs. Simultaneously, the liberating complementary strands continued to cyclic hybridization with the hairpin probe. This multiple signal amplification colorimetric strategy showed a wide linear range from 10 fM to 100 pM with a much lower detection limit of 3.13 fM for miRNA let-7a, which also performed well in a complex sample matrix. Most importantly, the naked eye could clearly distinguish the 10 fM color change caused by let-7a to be measured. Moreover, this approach could easily extend to multiple miRNAs with target-specific sequence substitutions. Therefore, this ultrasensitive visual strategy for miRNA demonstrated attractive potentials for promising applications in clinical diagnosis. [Display omitted] •We developed an ultrasensitive visualized biosensor for miRNA determination.•We combined the excellent signal amplification efficiency of entropy-driven strand displacement and visible solution.•The naked eye can clearly distinguish the color change caused by 10 fM of the target miRNA to be measured.•This method performs well in the serum sample, showing attractive potential in point-of-care test (POCT).