Concatenated DNA Circuit-Assembled DNAzyme as an Amplified Quencher for MicroRNA Detection

• Published in: ACS applied nano materials Vol. 5; no. 10; pp. 14602 - 14608
• Main Authors: Shen, Yanmei, Zhang, Lin, Ma, Demiao, Zhu, Qianqian, Meng, Hongmin, Qu, Lingbo, Li, Zhaohui, Ge, Jia
• Format: Journal Article
• Language: English
• Published: American Chemical Society 28.10.2022
• Subjects: DNAzyme; microRNA; hybridization chain reaction; catalyzed hairpin assembly; WS2 quantum dots
• ISSN: 2574-0970; 2574-0970
• DOI: 10.1021/acsanm.2c02973

In this study, we designed a fluorimetric assay for ultrasensitive determination of microRNA-141 based on WS2 quantum dots (WS2 QDs) and concatenated DNA circuit-assembled DNAzymes. WS2 QDs are synthesized using sodium tungstate and cysteine as W and S sources, and the use of biomass materials as a precursor is environment-friendly. The presence of microRNA-141 can trigger the CHA and HCR, leading to the formation of long dsDNA nanochains with numerous HRP-mimicking DNAzymes. The o-phenylenediamine structure was oxidized to 2,3-diaminophenazine by the DNAzymes. WS2 QDs could be quenched by 2,3-diaminophenazine via the inner filter effect. This method is highly sensitive for the analysis of microRNA-141 with a limit of detection of 2.7 fM. The designed strategy has no measurable response to four other microRNAs. The WS2 QDs-based sensor was used for the microRNA-141 assay in human serum and microRNA-141 expression in MDA-MB-231 cells. This newly developed biosensor shows great potential for the analysis of biomarkers and early diagnosis of microRNA-related diseases.