Hybrids made of defective nanodiamonds interacting with DNA nucleobases

The characteristics of hybrids made of a defective nanodiamond and a biomolecule unit are investigated in this work. Focus is given on the interaction between the nanodiamond and a DNA nucleobase. The latter is placed close to the former in two different arrangements, realizing different bonding types. The nanodiamond includes a negatively charged nitrogen-vacancy center and is hydrogen terminated. Using quantum-mechanical calculations, we could elucidate the structural and electronic properties of such hybrids. Our study clearly identifies the importance of the relative orientation of the two components, the nanodiamond and the nucleobase, in the complex in controlling the electronic properties of the resulting hybrid. The position of the defect at the center or closer to its interface with the nucleobase further controls the electronic orbitals around the defect center, hence its optical activity. In the end, we discuss the relevance of our work in biosensing.