A Density Functional Study on the Sensitivity of Small ZnO Nanoclusters to Sulfamethazine Considering Semilocal and Nonlocal Functionals

In this study, the possible application of small ZnO nanoclusters in the development of biosensors was investigated by density functional theory. Sulfamethazine is an antibiotic compound with an extensive range of prophylactic and therapeutic applications in animal husbandry. Because of the environmental risks associated with the overconsumption of antibiotics, the development of precise and selective detection methods is imperative. In this regard, the interaction of sulfamethazine and ZnO nanoclusters was investigated utilizing the semilocal functional of Perdew, Burke, and Ernzerhof and nonlocal functional developed by Vydrov and Voorhis. The results showed that the antibiotic can be adsorbed on ZnO nanoclusters. By considering van der Waals interactions, an increase was observed in adsorption energy when compared with the semilocal functional. Inclusion of van der Waals forces, however, did not alter the spatial configuration of the adsorbed molecule. The imaginary part of the dielectric function of ZnO nanoclusters was reduced upon antibiotic adsorption, which became more pronounced in the case of larger ZnO nanoclusters.