Biomediated Synthesis of ZnO Quantum Dots Decorated Attapulgite Nanocomposites for Improved Antibacterial Properties

Attapulgite (APT) is a natural one-dimensional clay mineral with good biocompatibility and has emerged as a promising nanomaterial for the construction of performance-enhanced nanocomposites. In this study, we developed a ZnO quantum dots-incorporated APT antibacterial nanocomposite by the Aloe vera extract-mediated green route. With the combined assistance of binding interactions of ZnO nuclei with APT and capping effect of active compounds in Aloe vera extract, the quantum-sized ZnO nanoparticles with hexagonal Wurtzite structure and sizes of <5 nm were uniformly decorated on the APT surface, resulting in a high-active antibacterial nanocomposite. The obtained ZnO/APT nanocomposites displayed favorable antibacterial activities, and the minimum inhibitory concentrations of the nanocomposite with ZnO loading of 20% against E. coli and S. aureus were 2.5 and 0.5 mg center dot mL(-1), respectively. This antibacterial performance was far better than that of APT and could almost be comparable to that of pure ZnO. For the green process, the phenolic compounds, proteins, and amino acids in Aloe vera extract were involved in the reduction and capping of ZnO, which contributed to a facile green strategy for preparation of the ZnO-modified APT nanocomposites. The present work provides new insight into the potential applications of APT in the antibacterial fields.