Environmental-friendly synthesis of Au-Ag alloy nanoparticles using Anethum graveolens leaf extract and their application to Surface Enhanced Raman Scattering (SERS)

We report an Environmental-friendly method for the synthesis of Au-Ag alloy nanoparticles (ANPs) by using Anethum graveolens fresh leaf extract as a reducing and stabilizing agent. The precursor solutions of Au (HAuCl4: 3H2O), Ag (AgNO3) and leaf extract were mixed by varying molar ratios and heated with continuous stirring at 70℃ for an hour leads a formation of Au-Ag ANPs with different atomic compositions. The periodic observation of colour changes indicated the formation of Au-Ag ANPs and got confirmed by the measurement of UV-Vis spectroscopy. The synthesized Au-Ag ANPs were characterized for morphological and elemental composition using Transmission Electron Microscopy (TEM) in conventional and scanning TEM (STEM) mode. The TEM image analysis shows that the synthesized Au-Ag ANPs were found to be in spherical shape with a broad size distribution with a mean size of 23 ± 18 nm. The energy dispersive X-ray (EDX) spectrometry in the STEM mode confirms the formation of Au-Ag ANPs . To show that these biosynthesized Au-Ag ANPs can be used as SERS (Surface Enhanced Raman Scattering) substrates, we carried out SERS studies using Crystal Violet (CV) and Rhodamine 6G (R6G) as test molecules by using 514.5 nm laser excitation wavelength. The detection level achieved was 50µM of CV and R6G, which would lead to exploring biosensing applications

Value Added Products Generation from Sugarcane Bagasse and Its Impact on Economizing Biorefinery and Sustainability of Sugarcane Industry

Augmenting value-added products generation with the biorefinery process of sugar cane by utilizing the by-products helps to achieve a more sustainable model of the sugarcane industry and in turn, contributes to the circular economy. Among the value-added products produced from sugarcane waste, functional foods offer additional health benefits besides their nutritional and calorific value. In recent years non-digestible sugars gained interest as potential prebiotic functional foods which benefit the host without increasing calorific value. These sugars are produced by the breakdown of carbohydrate polymers like cellulose and xylan, by thermochemical treatment or by enzymatic hydrolysis, or a combination of both. Sugar cane bagasse (SB) is an economical source of xylan which can serve as the substrate for xylooligosaccharides (XOS), xylobiose, xylitol, and ethanol. Cellulases, xylanases, and ligninases have wide applications in food processing, agro-fiber, pharmaceutical, and the paper and pulp industries including nutraceuticals production, where these enzymes provide eco-friendly alternatives to some chemical processes and help to reduce environmental impact. Conventional thermochemical methods for nutraceuticals production require chemicals that result in the release of toxic byproducts thus requiring additional steps for refining. In this context, the sustainable and eco-friendly processes for the production of nutraceuticals require employing biocatalysts like microbial enzymes or microbes as a whole, where in addition to averting the toxic byproducts the refining process requires lesser steps. The present chapter discusses the current research and challenges in the production of value-added products from sugarcane byproducts and their contribution to the sustainability of the sugarcane industry