Understanding structural and molecular properties of complexes of nucleobases and Au13 golden nanocluster by DFT calculations and DFT-MD simulation.

The characterization of the complexes of biomolecules and nanostructures is highly interesting and benefits the rational development and design of nano-materials and nano-devices in nano-biotechnology. In this work, we have used dispersion corrected density functional theory (DFT-D) as well as DFT based molecular dynamics simulations to provide an atomistic understanding of interaction properties of DNA nucleobases and Au13 nanocluster. Various active sites of interacting molecules considering their relative orientation and distance are explored. Our goal is to stimulate the binding characteristics between two entities and evaluate this through the interaction energy, the charge transfer, the electronic structure, and the specific role of the molecular properties of the nucleobase-Au13 system. The primary outcomes of this comprehensive research illuminated that nucleic bases have potent affinity for binding to the Au cluster being chemisorption type and following the trend: Adenine > Cytosine > Guanine > Thymine. The AIM analysis indicated that the binding nature of the interacting species was predominantly partial covalent and high polar. We discuss the bearing of our findings in view of gene-nanocarrier, biosensing applications as well as nanodevices for sequencing of DNA.