The surface plasmon resonance (SPR) effect endows gold nanoparticles (GNPs) with the ability to visualize biomolecules. In the present study, we designed and constructed a GNP probe to allow the semi-quantitative analysis of methylated tumor suppressor genes in cultured cells. To construct the probe, the GNP surfaces were coated with single-stranded DNA (ssDNA) by forming Au–S bonds. The ssDNA contains a thiolated 5′-end, a regulatory domain of 12 adenine nucleotides, and a functional domain with absolute pairing with methylated p16 sequence (Met-p16). The probe, paired with Met-p16, clearly changed the color of aggregating GNPs probe in 5 mol/L NaCl solution. Utilizing the probe, p16 gene methylation in HCT116 cells was semi-quantified. Further, the methylation of E-cadherin, p15, and p16 gene in Caco2, HepG2, and HCT116 cell lines were detected by the corresponding probes, constructed with three domains. This simple and cost-effective method was useful for the diagnosis of DNA methylation-related diseases.
Chen, K., Zhang, M., Chang, Y. N., Xia, L., Gu, W., Qin, Y., … Xing, G. (2016). Utilizing Gold Nanoparticle Probes to Visually Detect DNA Methylation. Nanoscale Research Letters, 11(1). https://doi.org/10.1186/s11671-016-1487-5