Valproic acid drug detection study through the pure and doped zinc oxide nanoclusters in gas and solvent phase: Density functional theory and thermodynamic study

In this study, to explore a potential sensor for the valproic acid drug, pure and doped zinc oxide nanoclusters (Zn₁₂O₁₂, AlZn₁₁O₁₂, and, GaZn₁₁O₁₂) were utilized in the gas and solvent phase using the density functional theory calculations. The adsorption energies were calculated at −21.87, −39.64, and −24.73 kcal mol⁻¹ for Zn₁₂O₁₂, AlZn₁₁O₁₂, and, GaZn₁₁O₁₂ complexes in their most stable configuration, respectively. Thermodynamic investigations were shown the interaction of valproic acid with the nanoclusters is spontaneous and exothermic. Sensor response investigation indicated 10.17, 6113.83, and 3.22 after the adsorption process for the Zn₁₂O₁₂, AlZn₁₁O₁₂, and, GaZn₁₁O₁₂, respectively. Thus, it is clear that the AlZn₁₁O₁₂ nanocluster demonstrated a significant sensor response. Further, the AlZn₁₁O₁₂ nanocluster had a practical short recovery time of 11.18 s. The solvent phase calculations indicated that these structures were stable in water. UV–vis calculation showed after the interaction of valproic acid with the AlZn₁₁O₁₂ spectrum shifted significantly to the higher wavelength region (red shift). Consequently, this study proposes the AlZn₁₁O₁₂ nanocluster as a potential candidate for valproic acid detection based on its suitable outcomes.