Detection of electronically equivalent tautomers of adenine base: DFT study

Graphical abstract: - Highlights: • DFT calculations have been performed on adenine and its rare tautomer Cu²⁺ complexes. • Interaction of A-Cu²⁺ and rA-Cu²⁺ complexes with AlN modified fullerene (C₆₀) have been studied briefly. • It is found that AlN modified C₆₀ could be used as a nanoscale sensor to detect these two A-Cu²⁺ and rA-Cu²⁺ complexes. - Abstract: In the present study, quantum chemical calculations were carried out to investigate the electronic structures and stabilities of adenine and its rare tautomer along with their Cu²⁺ complexes. Density Functional Theory (B3LYP method) was used in all calculations. The two Cu²⁺ complexes of adenine have almost similar energies and electronic structures; hence, their chemical differentiation is very difficult. For this purpose, interactions of these complexes with AlN modified fullerene (C₆₀) have been studied. Theoretical investigations reveal that AlN-doped C₆₀ may serve as a potentially viable nanoscale sensor for detection of the two Cu²⁺ complexes of adenine