A Computational Study on Cefalexin Antibiotic Adsorption on the Surface of Fullerene (C20)

In this study, the performance of fullerene (C20) as an adsorbent and sensor for the removal and detection of cefalexin was scrutinized by density functional theory computations. The negative values of adsorption energies showed cefalexin interaction with the nanostructure is experimentally possible. The negative values of enthalpy changes and Gibbs free energy variations demonstrated cefalexin adsorption on the surfaces of the adsorbent is exothermic and spontaneous. The values of thermodynamic constants indicated cefalexin interaction with C20 is reversible, equilibrium and two-sided. The NBO results showed cefalexin adsorption on the pristine fullerene is a physisorption because of non-formation of chemical bonds. The influence of temperature on the adsorption process was inspected and the obtained results showed cefalexin interaction with the nanostructure is more favorable at lower temperatures. The computed DOS spectrums showed the bandgap of C20 experienced a +296.9% decline from 1.950 (eV) to 7.750 (eV). Hence, this nanostructure can be employed as a sensing material for the development of new electrochemical sensors for the detection of cefalexin.