Binding of single/double stranded ct-DNA with graphene oxide‑silver nanocomposites in vitro: A multispectroscopic approach

The fundamental binding of single-stranded (ssDNA) and double-stranded DNA (dsDNA) with graphene oxide-Ag nanocomposites (GO-AgNCPs) has been systematically investigated by multi spectroscopic methods, i.e. ultraviolet-visible (UV-vis) absorption, fluorescence spectroscopy, and circular dichroism (CD). The experimental and theoretical results demonstrate that both ssDNA and dsDNA can be adsorbed onto the GO-AgNCPs surface. All of the evidence indicated that there were relatively strong binding of ssDNA/dsDNA with GO-AgNCPs. The article compares the differences in binding between the two types of DNA and the nanomaterials using spectroscopic and thermodynamic data. UV-vis absorption spectroscopy experiments indicate that the characteristic absorbance intensity of both ss DNA and ds DNA increases, but the rate of change in absorbance is different. The fluorescence results revealed that ss/dsDNA could interact with the GO-AgNCPs surface, in spite of the different binding affinities. The K