Ma Gui-min,Huo Li-wei,Tong Yin-xia,Wang Yu-cong,Li Cui-ping,Jia
Hong-xia
Abstract A novel strategy for microRNAs (miRNAs) detection has been developed utilizing duplex-specific nuclease-assisted signal amplification (DSNSA) and guanine-rich DNA-enhanced fluorescence of DNA-templated silver nanoclusters (AgNCs). The combination between target miRNA, DSNSA, and AgNCs is achieved by the unique design of DNA sequences. Target miRNA opens the hairpin structure of the Hairpin DNA probe (HP) by hybridizing with the HP and initiates the duplex-specific nuclease-assisted signal amplification (DSNSA) reaction. The DSNSA reaction generates the release of the guanine-rich DNA sequence, which can turn on the fluorescence of the dark AgNCs by hybridizing with the DNA template of the dark AgNCs. The fluorescence intensity of AgNCs corresponds to the dosage of the target miRNA. This is measured at 630 nm by exciting at 560 nm. The constructed method exhibits a low detection limit (~8.3 fmol), a great dynamic range of more than three orders of magnitude, and excellent selectivity. Moreover, it has a good performance for miR-21 detection in complex biological samples. Graphical abstract
A novel strategy for microRNAs (miRNAs) detection has been developed utilizing duplex-specific nuclease-assisted signal amplification (DSNSA) and guanine-rich DNA-enhanced fluorescence of DNA-templated silver nanoclusters (AgNCs).
Xiangyu Ma,Haoran Xu,Kun Qian,Martha Kandawa-Schulz,Weimin Miao,Yihong Wang
MicroRNAs (miRNAs) are important biomarkers in early diagnosis of disease. In this work, we developed a simple and effective electrochemical biosensor based on Au nanoparticles (AuNPs)/Carbon nitride nanosheet (CNNS) nanocomposite for the miRNAs detection. Duplex-specific nuclease (DSN) and hairpin structure probe were utilized to improve the sensitivity and selectivity respectively. In the presence of miRNA-21, the signal molecule could be released from the surface of the electrode and decrease the current peak in square wave voltammetry (SWV) test. Under the optimal conditions, the reported biosensor showed that the detection range of miRNA-21 is from 10 fM to 1 nM and detection limit is as low as 2.9 fM. Furthermore, the detection of miRNA-21 added in serum samples indicates the developed biosensor with good selectivity, stability and reproducibility which verify its potential to be used in the early diagnosis of diseases.
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