Synergistic Enhancement in Antibacterial Activity of Core/Shell/Shell SiO₂/ZnO/Ag₃PO₄ Nanoparticles

Abstract

Novel core/shell/shell SiO2/ZnO/Ag3PO4 nanoparticles (SZA‐NPs) were prepared through a facile reflux method involving sequential deposition of ZnO and Ag3PO4 to SiO2 spheres. The obtained SZA‐NPs were systematically characterized and used as the dual‐functional antibacterial agents for disinfection. Under visible‐light irradiation, the SZA‐NPs exhibit enhanced antibacterial activity for of Escherichia coli DH5α (E. coli) compared to that of Ag3PO4 or SiO2/ZnO in liquid phase and on agar plates. Quantitative analysis of Ag+ release from SZA‐NPs confirms the minor contribution of released silver ions to the antibacterial efficiency. On the other hand, chemical scavengers and photoluminescence studies suggest that radical oxygen species (ROS) also make major contribution to E. coli cell death. The enhanced antibacterial activity of the SZA‐NPs under visible‐light irradiation can be attributed to the synergistic effect of released silver ions and ROS generated from the excellent band matching between Ag3PO4 and ZnO. This work paves a new way for future design of highly efficient visible‐light induced antibacterial agents.

Exploring hierarchical porous silica-supported Ag3PO4 as high-efficient and environmental-friendly photocatalytic disinfectant

“…Escherichia coli was selected as a model pathogen to test disinfection efficiencies of the synthesized NPs. A chloride ion-free buffer solution was prepared and used through the whole disinfect experiments [18]. E.coli was first cultured to yield a suspension with viable cell density of about 10 9 CFU mL -1 [18].…”

“…Therefore, Ag 3 PO 4 immobilization and silver release control are crucial to explore it as an effective photocatalyst in a continuous disinfection operation. Till now, several practices have been explored as the support to anchor or immobilize Ag 3 PO 4 , such as CNTs, graphene, SiO 2 and hydroxyapatite (HA) [8,[12][13][14][15][16][17][18]. CNTs and graphene are expensive, and HA has a propensity for biofilm formation.…”

“…Silica is an excellent support candidate due to its low cost, easy preparation, good biocompatibility, materials inertness and easy surface modification [12,[19][20][21]. Although some preliminary studies have reported the deposition of Ag 3 PO 4 onto SiO 2 spheres, Ag 3 PO 4 aggregation and silver release still remain challenging [15,16,18,22].…”

Effect of Gd3+ doping on structural and photocatalytic properties of ZnO obtained by facile microwave-hydrothermal method

“…Among many oxides, zinc oxide (ZnO) is an important functional semiconducting material with a direct band gap of 3.37 eV, physical and chemical stability, weak cytotoxicity, high photosensitivity and piezoelectric properties [21,22]. This has made ZnO a good candidate for technological application such as energy conversion, photocatalysis, sensors, LED's and antibacterial properties [23][24][25][26][27][28]. Furthermore, ZnO has attracted attention for environmental remediation such as industrial wastewater treatment [29][30][31].…”

pH‐Transformed ZnO‐NPs /NaPTS: The First Room‐Temperature Brisk Synthesis of Flavanones in Aqueous Medium

“…ZnO nanowires are used in ultraviolet optoelectronic devices, such as nanolasers and sensors . It also acts as anti‐bacterial, anti‐oxidant, anti‐arthritic material . ZnO NPs were efficiently used in many reactions such as synthesis of coumarins, Mannich reaction, β‐phosphono malonates, Knoevenagel condensation, disubstituted 2,3‐quinalolin‐4(1 H )‐ones, 4‐amino‐5‐pyrimidinecarbonitriles, polyhydroquinoline, benzimidazole .…”