Photocatalytic activity of co‐doped NPs based on ZnO as a new class of anti‐microbial agents: Synthesis, characterization, kinetics, isotherm, and in silico molecular docking simulation

Abstract

This work effectively synthesized pure ZnO (PZ) and the co‐doped ZnO as Sm‐La CDZ NPs, La‐Sr CDZ NPs, and Sm‐Sr CDZ NPs using a hydrothermal technique. To characterize synthetic nanomaterials used, several techniques, including X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectra, ultraviolet and visible (UV/Vis), photoluminescence (PL), scanning electron microscopy (SEM), and graphs by energy dispersive X‐ray spectroscopy (XPS), Zeta potential, point of (pHpzc), and specific surface areas. Furthermore, the XRD, SEM, and TEM confirmed the hexagonal crystalline structure. However, XPS and EDX showed that Sm3+, La3+, and Sr2+ ions integrated into the ZnO lattice. The UV‐estimated band gaps increased in the co‐doped ZnO; BET surface areas declined. The Zeta potential proved the positivity surface charge of nanomaterials. Consequently, they utilized it to investigate the breakdown of reactive red 43 (RR43). The degradation percentages for PZ, Sm‐La CDZ NPs, La‐Sr CDZ NPs, and Sm‐Sr CDZ NPs were 72.88%, 82.63%, 87.08%, and 91.31%, respectively. According to the results, the Sm‐Sr CDZ NPs exhibit high photocatalytic activity. In addition, the pseudo‐first‐order kinetic model and Langmuir model were a better fit. The photocatalytic nanomaterials were also recyclable, which added to their stability. The prepared nanoparticles were evaluated against four bacterial strains and two fungal pathogenic, and the result exhibited a broad spectrum against tested strains. The co‐doped NPs revealed MIC values ranging between1.95 and 62.5 μg/mL and MBC values of (31.3–250 μg/mL) compared with PZ (MIC = 7.81–62.5 μg/mL and MBC = 31.3–250 μg/mL) against bacterial strains. Surprisingly, most of these NPs expressed bacteriocidal and fungicidal potential. In silico molecular docking simulation suggested that the antibacterial activity may be related to the inhibition of DNA gyrase, cell wall synthesis (Upps and Fos A), and biofilm activity (PqsR).