title: A split recognition mode combined with cascade signal amplification strategy for highly specific, sensitive detection of microRNA.
abstract: MicroRNAs (miRNAs) are vital for many biological processes and have been regarded as cancer biomarkers. Specific and sensitive detection of miRNAs is essential for cancer diagnosis and therapy. Herein, a split recognition mode combined with cascade signal amplification strategy is developed for highly specific and sensitive detection of miRNA. The split recognition mode possesses two specific recognition processes, which are based on toehold-mediated strand displacement reaction (TSDR) and direct hybridization reaction. Two recognition probes, hairpin probe (HP) with overhanging toehold domain and assistant probe (AP), are specially designed. Firstly, the toehold domain of HP and AP recognize part of miRNA simultaneously, accompanied with TSDR to unfold the HP and form the stable DNA Y-shaped junction structure (YJS). Then, the AP in YJS can further act as primer to initiate strand displacement amplification, releasing numerous trigger sequences. Finally, the trigger sequences hybridize with padlock DNA to initiate circular rolling circle amplification and generate enhanced fluorescence responses. In this strategy, the dual recognition effect of split recognition mode guarantees the excellent selectivity to discriminate let-7b from high-homology sequences. Furthermore, the high amplification efficiency of cascade signal amplification guarantees a high sensitivity with the detection limit of 3.2 pM and the concentration of let-7b in total RNA sample extracted from Hela cells is determined. These results indicate our strategy will be a promising miRNA detection strategy in clinical diagnosis and disease treatment.
authors: Key Laboratory for Colloid and Interface Chemistry of Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100 PR China.
authors: Rui
authors: R
authors: Wang
authors: School of Pharmaceutical Sciences, Shandong University, Jinan, 250012 PR China.
authors: Lei
authors: L
authors: Wang
authors: Key Laboratory for Colloid and Interface Chemistry of Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100 PR China.
authors: Haiyan
authors: H
authors: Zhao
authors: Key Laboratory for Colloid and Interface Chemistry of Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100 PR China. Electronic address: wjiang@sdu.edu.cn.
authors: Wei
authors: W
authors: Jiang
mesh_terms: D015342:DNA Probes / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006367:HeLa Cells; D006801:Humans; D035683:MicroRNAs / Q000032:analysis* / Q000235:genetics*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D012334:RNA, Neoplasm / Q000032:analysis* / Q000235:genetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017423:Sequence Analysis, RNA / Q000295:instrumentation* / Q000379:methods
chemical_list: D015342:DNA Probes; D035683:MicroRNAs; D012334:RNA, Neoplasm
keywords: Cascade signal amplification; MicroRNA; Split recognition mode; Toehold-mediated strand displacement reaction; Y-shaped junction structure