Harnessing formaldehyde detection: novel metal-doped coronene sensors to combat pollution and enable early lung cancer diagnosis.

Formaldehyde (FA) is a critical volatile organic compound, serving both as a significant environmental pollutant and as a non-invasive breath biomarker for early-stage lung cancer detection. Developing highly sensitive and selective sensors for FA is therefore paramount for environmental monitoring and transformative medical diagnostics. This study employs comprehensive density functional theory (DFT), and time dependent DFT (TD-DFT) calculations to design and evaluate novel metal-doped coronene (Cor) nanostructures (Be-Cor, Mg-Cor, and Ca-Cor) as advanced dual-purpose platforms for FA sensing and capture. Our systematic investigation reveals that alkaline earth metal doping, particularly with calcium and magnesium, dramatically enhances the electronic and optical properties of coronene. Ca-Cor and Mg-Cor exhibit exceptionally strong and spontaneous adsorption of FA, with profoundly negative adsorption energies (down to − 4.75 eV) and Gibbs free energies, indicating an essentially irreversible chemisorption process ideal for permanent removal. These complexes also demonstrate a remarkable charge-transfer-driven interaction, leading to the emergence of intense new absorption bands in the visible region (488 nm and 518 nm), positioning them as excellent candidates for colorimetric sensors with a clear, naked-eye detectable response. Furthermore, Ca-Cor shows a significant positive change in electrical conductivity upon FA binding, providing a robust electrochemical signal. In contrast, Be-Cor and pristine coronene exhibit only weak, reversible physisorption. The superior performance of Ca-Cor and Mg-Cor is rationalized through detailed analyses of frontier molecular orbitals, quantum descriptors, Natural Bond Orbital interactions, and thermodynamic parameters. This computational work establishes Ca- and Mg-doped coronene as the most promising nanomaterials for the next generation of highly sensitive, selective, and multifunctional sensors, capable of both detecting and sequestering formaldehyde, with direct applications in environmental remediation and early, non-invasive lung cancer diagnosis.