Interaction of human serum albumin with silver nanoparticles functionalized with polyvinylthiol

The interaction of novel polyvinylthiol coated silver nanoparticles (Ag-PVT) with human serum albumin (HSA) has been investigated by fluorescence (intrinsic, extrinsic and synchronous), UV-visible, and circular dichroism spectroscopies. Analysis of the fluorescence quenching data of HSA by Ag-PVT nanoparticles using Stern-Volmer method revealed the formation of 1:1 ground state complex. Evaluation of binding parameters and binding energy indicated that the binding reaction was exothermic. On the basis of fluorescence measurements it was concluded that hydrophobic forces play crucial role in stabilizing the complex. The binding distance was calculated by using Förster resonance energy transfer (FRET) theory. The conformational changes of HSA were obtained qualitatively as well as quantitatively using synchronous fluorescence and CD, respectively. The HSA underwent partial unfolding in presence of Ag-PVT nanoparticles.