Theoretical studies on the electronic and optoelectronic properties of DNA/RNA hybrid-metal complexes

The electronic and optoelectronic properties of DNA/RNA functionalized conductive metal adatoms were studied using DFT and TDDFT methods. Four hybrid structures were selected from the experimental work on RNA microchips. The occupied number of states by the system at each energy level were studied by Density of States (DOS). Atom-in Molecules (AIM) analysis and Noncovalent Interaction (NCI) PLOT were used to study the interaction in these complexes. Results indicated that HOMO-LUMO (HL) Gap is larger for C1-C4 complexes as compared to the HL gap for DNA/RNA hybrid-metal interacted complexes. This clearly indicates strong DNA/RNA-metal interaction, which is also observed in NCIPLOT analysis. Al and Au are chemically bonded to DNA/RNA hybrids, while the adsorption of Cu is between weak chemisorption and strong physisorption. The interacted bond distance of DNA/RNA-(Al, Cu) complexes are smaller than the bond distance of DNA/RNA-Au complexes. AIM analysis predicts noncovalent interaction for the studied complexes. TDDFT results indicate that few complexes can be used as fluorescent biomarkers as the absorption and emission wavelength lies in the visible region. (C) 2020 Elsevier Ltd. All rights reserved.