Multi-core-shell composite SnO₂NPs@ZIF-8: potential antiviral agent and effective photocatalyst for waste-water...

With increasing environment pollution and bacterial transmitted viral diseases globally, the development of new, effective, and low-cost materials/strategies is the current major challenge. To combat with this alarming problem, three new multi-functional and thermally stable SnO₂NPs@ZIF-8 composites (NC1, NC2, and NC3) were synthesized by a facile and sustainable approach involving in situ encapsulation of SnO₂NPs (150, 300, and 500 μL suspension in methanol) within zeolitic imidazole framework at room temperature. The morphology and crystallinity of ZIF-8 remained unchanged upon the proper encapsulation of SnO₂NPs in its matrix. Herein, for the first time, the antiviral potential of ZIF-8 and SnO₂NPs@ZIF-8 against chikungunya virus is reported by investigating their cytotoxicity against Vero cell line (employing MTT ((3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide)) assay). The maximum non-toxic doses were 0.04 mg mL^-1 for ZIF-8 and SnO₂NPs@ZIF-8 and 0.1 mg mL^-1 for SnO₂NPs. Further, NC1 exhibited (based on plaque assay) reduction in viral load/titers up to > 80% during post-treatment and > 50% during pre-treatment, greater than that of ZIF-8 and SnO₂NPs due to synergistic effect. Further, NC1 (10 mg) exhibited enhanced photocatalytic efficiency (≥ 96%) for degradation of methylene blue (0.5 × 10^-5 M) at pH ˃ 7.0. The probable mechanism for their antiviral activity and photocatalytic activity has been discussed. The multi-functional composites can effectively be used to reduce water pollution and as remedy for mosquito/bacterial transmitted viral diseases.