Progress of metal nanoclusters in nucleic acid detection

The development and application of metal nanoclusters (MNCs) in nucleic acid testing in the past 10 years were summarized. Fluorescence enhancement and red shift can occur when G-rich sequence get close to Ag NCs or the complementary DNA strand hybridizes with Ag NCs tail strand, which can be used to identify the nucleic acid. Ag NCs with abasic site in DNA duplex can distinguish mutant gene such as cancer supression gene p53. Ag NCs with auxiliary DNA can be used to detect miR-21, miR-16-5p, miR-19b-3p, miR-141. Cu NCs / Cu NPs can recognize miRNA-155, miR-21 and miR-let-7d without auxiliary DNA. Au NCs can identify H1N1 gene fragments by fluorescence quenching caused by proximity to G-rich sequence. Besides, Au NCs can recognize miRNA-21 and let-7a. SsDNA MNCs adsorbed on the surface of GO, CNPs oxide can be used to identify HBV and HIV gene fragments. Addition of enzymes or auxiliary amplification technologies was popular way to improve sensitivity of probe. Ag NCs combined with TAIEA has the best performance and can obtain LOD as low as aM for miRNA.