New sensors based on DNA base pairs: DFT, QTAIM, and NCI-RDG study.

contextToxic agents in the environment represent a serious threat to human life and pose a major problem, which has led scientists to conduct continuous research into methods for detecting and removing them from the environment. For example, H₂S, SO₂, NH₃, CO, CO₂, NO, and NO₂ are toxic agents commonly found in their gaseous state. Enhancing environmental sensing is, therefore, essential for protecting the ecosystem. In this context, we suggest new complexes of copper and cobalt based on thymine base pair: [thym-Co-thym] and [thym-Cu-thym] as sensors to detect and to attract toxic agents. Our theoretical study demonstrates the potential of the proposed complexes to act as biosensors capable of capturing toxic agents from the environment, as supported by various quantum chemistry methods, including quantum theory of atoms in molecules (QTAIM), reduced density gradient (RDG), natural bond orbitals (NBO), and non-covalent interaction (NCI) analysis. Orbital interaction is favored for H

methodsStudied structures are optimized at DFT/M06-2x/6-311 + G(d,p) level of theory implemented in Gaussian16. The pseudopotential LanL2DZ is used for metals copper and cobalt. [thym-Cu-thym] and [thym-Co-thym] complexes are reoptimized toward considered species and in the presence of humidity (H