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

Area of Science:

• Computational Chemistry
• Environmental Science
• Materials Science

Background:

• Toxic gaseous agents (H₂S, SO₂, NH₃, CO, CO₂, NO, NO₂) pose significant environmental and health risks.
• Development of effective environmental sensing technologies is crucial for ecosystem protection.
• Existing methods for detecting toxic gases require enhancement for improved sensitivity and specificity.

Purpose of the Study:

• To theoretically investigate novel copper and cobalt complexes based on thymine base pairs, [thym-Co-thym] and [thym-Cu-thym].
• To evaluate the potential of these complexes as biosensors for detecting and capturing toxic gaseous agents.
• To analyze the nature and strength of interactions between the proposed complexes and various toxic agents using advanced computational methods.

Main Methods:

• Density Functional Theory (DFT) calculations at the M06-2x/6-311+G(d,p) level of theory.
• Quantum Theory of Atoms in Molecules (QTAIM) and Reduced Density Gradient (RDG) analyses to characterize interactions.
• Natural Bond Orbital (NBO) analysis and UV-Vis absorption spectra calculations (TD-DFT) to understand electronic properties and spectral responses.

Main Results:

• Both [thym-Co-thym] and [thym-Cu-thym] complexes exhibit favorable interactions with toxic agents, particularly SO₂.
• Non-covalent interactions, including hydrogen and van der Waals bonding, were identified between the complexes and toxic agents.
• Specific spectral signatures were observed for the detection of different gases: [thym-Co-thym] for NO₂, NO, SO₂, and [thym-Cu-thym] for H₂S, HCN.

Conclusions:

• The studied copper and cobalt-thymine complexes show significant potential as effective biosensors for environmental toxic gas detection.
• Computational analyses confirm the stability and interaction capabilities of these complexes, supporting their sustainable synthesis.
• The distinct spectral responses provide a basis for developing selective and sensitive gas sensing technologies.