DNA adduct identification using gold-aptamer nanoprobes

The optical and physico-chemical properties of gold nanoparticles (AuNPs) have prompted new and improved approaches which have greatly evolved the fields of biosensing and molecular detection. In this study, the authors took advantage of AuNPs´ ease of modification and functionalised it with selected DNA aptamers using a salt aging method to produce gold-aptamer nanoprobes. After characterisation, these nanoprobes were subsequently used for biomolecular detection of glycidamide (GA)-guanine (Gua) adducts generated in vitro. The results are based on differences in nanoprobe stabilisation against salt-induced aggregation, similar to the non-cross-linking method developed by Baptista for discrimination of specific sequences. Alkylated Guas were efficiently discriminated from deoxyguanosine and GA in solution. Despite this, a clear identification of DNA adducts derived from genomic DNA alkylation has proven to be a more challenging task.