Building Polyvalent DNA‐Functionalized Anisotropic AuNPs using Poly‐Guanine‐Mediated In‐Situ Synthesis for LSPR‐Based Assays: Case Study on OncomiR‐155

Abstract

DNA-functionalized gold nanoparticles (DNA-AuNPs) hold great promise for numerous biomedical applications, especially the building of well-defined nanosystems. Previously reported methods for the preparation of DNA-AuNPs all rely on the use of DNA-bearing free thiol or disulfide groups at their 3 0 /5 0 ends. But here we report a novel polyvalent DNA-AuNPs conjugation approach by in-situ fast synthesis of AuNPs at the polyguanine (G 12 ) strands. As confirmed by both TEM images and gel electrophoresis analysis, many poly G strand can form an individual anisotropic AuNP and so each AuNP functionalized with a dense layer of DNA, resulting in the formation of polyvalent (p)DNA-AuNPs. The general applicability of this novel approach was further verified in hybridization test and UV-Vis spectroscopy results show that pDNA-AuNPs conjugation is more attractive in biomedical diagnosis and specific sequence detection like microRNA-155 by using an extra-strand poly G with "sticky end" that are complementary to the target sequence.

Exploitation of N-Gene of SARS-CoV-2 to Develop a New Rapid Assay by ASOs@AuNPs

“…A 20-base length antisense oligonucleotide strand was designed with extra 12 guanine to form AuNPs. A previous study clearly demonstrated that polyguanine (G 12 ) tails had a reliable efficiency for the synthesis of polyvalent DNA@anisotropic AuNPs. Thus, based on this rapid method, 5 μL of ASO 1 and 2 and 3 and 4 (100 μM) were added to 20 μL of HEPES buffer (5 mM), respectively, in four different reaction microtubes.…”