Fabrication and Characterization of Ag-Graphene Nanocomposites and Investigation of Their Cytotoxic, Antifungal and Photocatalytic Potential.

In the present study, we aimed to synthesize (Ag)1-x(GNPs)x nanocomposites in variable ratios (25% GNPs-Ag, 50% GNPs-Ag, and 75% GNPs-Ag) via an ex situ approach to investigate the incremental effects of GNPs (graphene nanoparticles) on AgNPs (silver nanoparticles). The prepared nanocomposites were successfully characterized using different microscopic and spectroscopic techniques, including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet spectroscopy, and Raman spectroscopic analysis. For the evaluation of morphological aspects, shape, and percentage elemental composition, SEM and EDX analyses were employed. The bioactivities of the synthesized nanocomposites were briefly investigated. The antifungal activity of (Ag)1-x(GNPs)x nanocomposites was reported to be 25% for AgNPs and 66.25% using 50% GNPs-Ag against Alternaria alternata. The synthesized nanocomposites were further evaluated for cytotoxic potential against U87 cancer cell lines with improved results (for pure AgNPs IC50: ~150 µg/mL, for 50% GNPs-Ag IC50: ~12.5 µg/mL). The photocatalytic properties of the nanocomposites were determined against the toxic dye Congo red, and the percentage degradation was recorded as 38.35% for AgNPs and 98.7% for 50% GNPs-Ag. Hence, from the results, it is concluded that silver nanoparticles with carbon derivatives (graphene) have strong anticancer and antifungal properties. Dye degradation strongly confirmed the photocatalytic potential of Ag-graphene nanocomposites in the removal of toxicity present in organic water pollutants.

Synthesis and Characterization of Silver and Graphene Nanocomposites and Their Antimicrobial and Photocatalytic Potentials.

Microbial pathogens and bulk amounts of industrial toxic wastes in water are an alarming situation to humans and a continuous threat to aquatic life. In this study, multifunctional silver and graphene nanocomposites (Ag)1-x(GNPs)x [25% (x = 0.25), 50% (x = 0.50) and 75% (x = 0.75) of GNPs] were synthesized via ex situ approach. Further, the synthesized nanocomposites were explored for their physicochemical characteristics, such as vibrational modes (Raman spectroscopic analysis), optical properties (UV visible spectroscopic analysis), antibacterial and photocatalytic applications. We investigated the antimicrobial activity of silver and graphene nanocomposites (Ag-GNPs), and the results showed that Ag-GNPs nanocomposites exhibit remarkably improved antimicrobial activity (28.78% (E. coli), 31.34% (S. aureus) and 30.31% (P. aeruginosa) growth inhibition, which might be due to increase in surface area of silver nanoparticles (AgNPs)). Furthermore, we investigated the photocatalytic activity of silver (AgNPs) and graphene (GNPs) nanocomposites in varying ratios. Interestingly, the Ag-GNPs nanocomposites show improved photocatalytic activity (78.55% degradation) as compared to AgNPs (54.35%), which can be an effective candidate for removing the toxicity of dyes. Hence, it is emphatically concluded that Ag-GNPs hold very active behavior towards the decolorization of dyes and could be a potential candidate for the treatment of wastewater and possible pathogenic control over microbes. In the future, we also recommend different other in vitro biological and environmental applications of silver and graphene nanocomposites.

Effect of Endoxylanase and Iron Oxide Nanoparticles on Performance and Histopathological Features in Broilers.

Endoxylanase enzyme is used as poultry feed additive to degrade anti-nutritional factors like non-starch polysaccharides. Moreover, iron is one of the most important trace elements, and its deficiency can lead to various pathological conditions and stunted growth. In the current study, a combination of xylanase and iron nanoparticles is used to assess the overall effect on poultry growth. Endoxylanase enzyme was obtained from Aspergillus awamori SAIB-17 (identified on the basis of internal transcribed spacer (ITS) sequence analysis). The characterization of purified endoxylanase revealed that the Km and Vmax were 0.25 g/ml and 833.33 nkat/ml/s, respectively. Effect of pH and temperature showed that pH 4.5 and temperature 45 °C was best for enzyme activity. Iron nanoparticles were synthesized by co-precipitation of ferric chloride and ferrous chloride. Characterization of nanoparticles using X-ray diffraction (XRD) and SEM revealed that the mean diameter of synthesized iron nanoparticles was around 50 nm. These nanoparticles have no inhibitory effect on endoxylanase up to concentration of 20 ppm. Iron oxide nanoparticles along with endoxylanase were used as additives in different concentrations and were fed to the groups of broiler chicks. It was observed that the group fed with 40 nkat of endoxylanase and 15 ppm of iron nanoparticles showed 54.5% (2010 ± 103.58) more weight gain by the fifth week as compared with the control group. The iron analysis in the muscles showed no increase in iron concentration while histopathology slides showed no morphological changes in liver cells. The combination of iron oxide nanoparticles and xylanase proved to have great potential to be used in poultry feed for large-scale meat production without any toxicological effects.