Computational study of metal doped coronene quantum dots for formaldehyde sensing and adsorption in medical and environmental applications

In this study, the ability of pure and aluminum- and zinc-doped coronene as dual-purpose adsorbent/sensor platforms for formaldehyde (FA) detection in environmental and biomedical applications was computationally studied. All molecular structures were optimized individually and in combination with FA using density functional theory (DFT) at the B97D/6-311 + G(d) level of theory in the gas and water phases, and validated using WB97XD calculations. Analyses included geometric optimization, coherence energy, IR and UV spectra (TD-DFT), MEP mapping, HOMO-LUMO distributions, DOS plots, reactivity descriptors, dipole moment and polarizability, adsorption energy, recovery time, and electrical conductivity. Intermolecular interactions were analyzed using the theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) analyses. Among all structures, Al.Coronene@FA exhibited the strongest sensing ability with the highest adsorption energy of − 39.57 kcal/mol (water phase) and − 44.43 kcal/mol (gas phase), along with an extremely long recovery time of 1.08 × 1013 s (water) and 3.93 × 1016 s (gas). This was paired with the highest electrical conductivity of 2.85 × 109 A m− 2 (water), confirming a strong charge-transfer mechanism. Conversely, Zn.Coronene@FA showed moderate adsorption (− 6.16 kcal/mol) and fast recovery time (3.34 × 10− 12 s), making it favorable for reusable sensing platforms. Optical studies revealed pronounced redshifts in λmax upon FA adsorption, particularly for Al.Coronene@FA with λmax = 579 nm and 694 nm (water phase), indicating excellent colorimetric detection capability. Overall, the combination of strong adsorption ability, high electrical conductivity, significant spectral shifts, and charge transfer indicates Al-doped coronene is a highly promising material for formaldehyde sensing, whereas Zn-doped coronene is better suited for rapid-response reusable sensors. These computational results establish a reliable foundation for developing coronene-based sensing and adsorption platforms for environmental and biomedical applications.