Multiplexed fluorescence detection of microRNAs based on novel distinguishable quantum dot signal probes by cycle amplification strategy

MicroRNA (miRNA) is a biomarker that has great potential for the diagnosis and prediction of different cancers. Exploring a rapid and specific method for detecting miRNA has become a research hotspot. In this study, a novel strategy for simultaneous fluorescence detection of dual target miRNAs (miRNA-141 and miRNA-21) based on two distinguishable [email protected] and CdTe quantum dot (QD) probes by target recycling amplification strategy was reported. The hairpin (HP) DNA was firstly linked to the magnetic [email protected] ([email protected]) complex, then the present target miRNAs hybridized with HP, which then initiated the exonuclease III-aided target recycling process, leading to the generation of numerous intermediate DNA sequences (s1) on [email protected] Subsequently, a large number of QDs fluorescence probes were introduced to hybridize with s1, which will further trigger the scission with addition of Nb.BbvCI. Through convenient magnetic separation, much amplified fluorescence signal of QDs was detected, which has a quantitative relation with the target miRNAs. Importantly, two kinds of distinguishable fluorescent QDs probes were applied to the simultaneous detection of dual miRNAs by cycling amplification strategy. Thus, the proposed fluorescence method could be used to rapidly detect miRNA-141 and miRNA-21 with high sensitivity, and effectively distinguished single-base-mismatched miRNA sequences with high specificity. Therefore, this strategy holds great potential for sensitive, efficient and convenient detection of various tumor markers in clinical application.