DFT investigation of glucose adsorption and sensing on C24, Be12O12, and Ca12O12 nanocages (vacuum and aqueous media)

A comparative density functional theory study was performed to investigate the adsorption and sensing behavior of glucose on C24, Be12O12, and Ca12O12 nanocages in vacuum and aqueous media. Geometry optimization and electronic structure calculations were carried out at the B3LYP/6–31 + G(d, p) level, with water effects incorporated through an implicit solvation model. The adsorption process was analyzed using adsorption energies, optimized interaction distances, frontier molecular orbitals, Density of states, global reactivity descriptors, charge transfer, and recovery-time considerations. The results show that glucose interacts weakly with C24, with adsorption energies of about − 0.57 eV in vacuum and − 0.68 eV in water, indicating physisorption. In contrast, much stronger adsorption is found for Be12O12 and Ca12O12, with adsorption energies of − 1.52/− 1.79 eV and − 1.16/− 1.33 eV in vacuum/water, respectively, suggesting stronger interfacial interactions with partial chemisorption character. Adsorption also modifies the electronic properties of the nanocages, particularly for Ca12O12, which exhibits a favorable balance between electronic response and reversible desorption. Recovery-time analysis further indicates that C24 allows very fast desorption but may suffer from limited sensitivity, whereas Be12O12 binds glucose too strongly for efficient sensor reuse. Among the three systems, Ca12O12 emerges as the most promising candidate for practical glucose sensing, especially under aqueous conditions where both sensitivity and reusability are required.