The promising therapeutic implications of nanoparticles have spurred their development for biomedical applications. An eco-friendly methodology synthesizes gold nanoparticles using Cordyceps militaris, an edible mushroom (Cord-Au-NPs), using a quality-by-design approach (central composite design). UV-visible spectroscopy analysis revealed an absorption peak at 540–550 nm, thus confirming the synthesis of gold nanoparticles. Cord-Au-NPs have a crystalline structure, as evidenced by the diffraction peaks. The zeta potential value of −19.42 mV signifies the stability of Cord-Au-NPs. XRD study shows gold facets and EDX analysis revealed a strong peak of spherical nanoparticles in the gold region with a mean particle size of 7.18 nm and a polydispersity index of 0.096. The obtained peaks are closely associated with phenolic groups, lipids, and proteins, as examined by FTIR, suggesting that they function as the reducing agent. Cord-Au-NPs exhibited dose-dependent antioxidant, antidiabetic, and antibacterial activity. The method is eco-friendly, nontoxic, less time-consuming, and does not use synthetic materials, leading to higher capabilities in biomedical applications.
Wastewater generated by the textile industry contains substantial amounts of organic pollutants, particularly synthetic dyes, which pose serious risks to human health and aquatic ecosystems. The removal of these contaminants from water bodies is essential, necessitating the development of cost-effective and efficient treatment strategies. The present study focuses on the development of cost-effective nanostructured materials for dye removal from wastewater and antibacterial activity against both Gram-positive and Gram-negative bacteria. A NiFe2O4/rGO heterojunction was synthesized via a one-pot hydrothermal method and characterized to assess its structure, morphology and optical properties. The synthesized material was evaluated for its catalytic removal of methylene blue (MB) and malachite green (MG) dyes and NiFe2O4/rGO (10%) showed 98.01% and 98.53% removal of MB and MG dyes, respectively, in 120 min. The catalytic removal rate of NiFe2O4/rGO (10%) heterojunction was much faster (98.01%; 98.53%) than the pure NiFe2O4 (73.43%; 73.16%) under visible light illumination. The substantial stability and reusability of the heterojunction were assessed through repeated photocatalytic degradation cycles. Its antibacterial activity was evaluated against the selected multidrug-resistant microorganisms, with NiFe2O4/rGO exhibiting significant zones of inhibition against both bacterial strains. These findings support the potential application of NiFe2O4/rGO in wastewater treatment, particularly for the removal of organic dyes and bacterial contaminants.