Detection of base pairing of an oxidatively damaged guanine using colloidal stability change of DNA-linked polymer micelles

A DNA-linked polymer micelle was prepared through a phase transition of an amphiphilic copolymer consisting of single-stranded DNA as the hydrophilic part and thermo-responsive poly(N-isopropylacryl-amide) as the hydrophobic part. Duplex formation on the surface of micelle decreased the colloidal stability, whereas a terminal single-base mismatch at the interface between the DNA shell and the disperse medium increased the colloidal stability. Based on this change, we successfully detected base pairing of 7,8-dihydro-8-oxo-2'-deoxyguanine with adenine. This method will be useful for discovering a Watson-Crick or non Watson-Crick base pair of an unknown oxidative-damaged base with each four canonical one.