Simple and sensitive detection of microRNA based on guanine-rich DNA-enhanced fluorescence of DNA-templated silver clusters

Recent Advances in the Preparation and Application of DNA-Encoded Metal Nanoclusters

“…It is worth noting that nonfluorescent DNA-Ag NCs can be lit up by adjacent Grich DNA strands [61,63] or ligand displacement [37]. In addition, spectral conversion of DNA-Ag NCs by adjacent poly G sequence occurred, namely from yellow-emitting silver nanoclusters (Y-Ag NCs) to red-emitting silver nanoclusters (R-Ag NCs), no matter what the hybridization sequence was [61] (Figure 1A).…”

“…In recent years, various amplification strategies, such as polymerase chain reaction (PCR) [82], loop-mediated isothermal amplification (LAMP) [83], and nuclease-assisted signal amplification (DSNSA) [63], have been successfully integrated into DNA-Ag NCbased analytical systems to achieve a limit of detection (LOD) as low as fM or aM. For Moreover, varieties of bioanalytical platforms have been constructed [2,64,78] on the basis of direct fluorescence regulation of DNA-MNCs.…”

“…In recent years, various amplification strategies, such as polymerase chain reaction (PCR) [82], loop-mediated isothermal amplification (LAMP) [83], and nuclease-assisted signal amplification (DSNSA) [63], have been successfully integrated into DNA-Ag NCbased analytical systems to achieve a limit of detection (LOD) as low as fM or aM. For example, a very simple and sensitive homogeneous detection strategy for microRNA (miRNA) has been established based on the fluorescence enhancement of Ag NCs by Grich DNA and in combination with DSNSA [63]. As shown in Figure 2A, a DNA probe, DNA-Ag NCs, and a duplex-specific nuclease (DSN) were involved.…”

Specific Adsorption of Magnetic Fe3O4@hydroxyapatite Nanocomposites to a Hybridized Duplex for Immobilization and Label-Free Electrochemical Biosensing of MicroRNA

“…3 Numerous pathological studies have shown that the abnormal expression of miRNA let-7a in tumor cells and serum is correlated to many cancers, such as hepatocellular carcinoma (HCC), 4 breast cancer, 5 and pancreatic cancer, 6 making miRNA let-7a one of crucial cancer biomarkers. At present, a variety of methods have been developed to detect miRNA let-7a, such as electrochemiluminescence, 7,8 fluorescence assays, 9 and electrochemical methods. 10,11 Compared to the other methods, the electrochemical biosensing technology has the advantages of simpleness, low cost, and high sensitivity, which are more conducive to the establishment of practical analytical devices.…”