The dual role of porphyrin nanocarriers in favipiravir sensing and drug delivery: a DFT perspective

Targeted drug delivery has emerged as a crucial area of research in medicinal chemistry, offering the potential to minimize side effects and improve therapeutic efficiency. For this purpose, we have performed density functional theory (DFT) calculations to investigate the adsorption and drug delivery behavior of porphyrin for the favipiravir (FAP) drug. The adsorption energy studies reveal negative adsorption energies ranging from −17.123 kcal mol⁻¹ to −22.236 kcal mol⁻¹, indicating the physisorption nature of the interactions between the FAP and the PPR surface. A comprehensive analysis of frontier molecular orbitals (FMOs) suggests a reduction in the energy gap from 2.72 eV for PPR to the lowest energy gap of 2.62 eV for FAP-Am@PPR. The density of states (DOS) further confirms the shifting of molecular orbitals, which induces changes in the Fermi level energy (E_FL) of the studied systems. An increase in the dipole moment values was observed in the solvent phase compared to the gas phase. Notably, all the designed systems show short recovery times, with the shortest being 9.99 × 10⁻¹⁰ s for FAP-Am@PPR. Topological analysis (NCI and QTAIM) predicts the weak covalent nature of interactions between the drug and adsorbent. Among various modified systems, FAP-Am@PPR and FAP-O@PPR exhibit notably high values of electrical conductivity (4.68 × 10¹² and 4.67 × 10¹² S m⁻¹) and sensitivity response (0.020 and 0.018), due to their narrow energy gap, which reveals the potential of porphyrin as a drug delivery vehicle in these configurations. These findings demonstrate the potential of porphyrins as drug delivery vehicles for the antiviral FAP drug.