No abstract

The antagonistic side effects of chemical medications led to the search for safe strategies such as biogenic agents. Correspondingly, this study aims to create biogenic, appropriate, auspicious and innovative therapeutic agents like Galaxaura elongata {GE}, Turbinaria ornata {TO} and Enteromorpha flexuosa {EF} macroalgae-based silver nanoparticles (Ag-NPs). The Ag+ reduction and the creation of Ag[GE]-NPs, Ag[TO]-NPs and Ag[EF]-NPs have been validated using UV–visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and zeta potential analysis, and the chemical composition of macroalgae crude extracts was estimated through gas chromatography–mass spectrometry (GC–MS). Further, macroalgae-based Ag-NPs were tested for their free radical scavenging activity DPPH, ABTS, anticancer activity in human liver carcinoma (HepG2) cell line, distinctive inflammation forms and elevated α-amylase. Results showed that the biosynthesized Ag-NPs have unique mechanical and physicochemical characters attributed to their high relative surface area, nanosized dimensions and spherical shape. At dose of 200 µg/mL, the DPPH radical scavenging capacity was maximized with Ag[TO]-NPs (67.26%); however, Ag[EF]-NPs was the most potent as ABTs scavenger (97.74%). Additionally, Ag[GE]-NPs had the maximum proteinase inhibitory action with 59.78%. The 1000 µg/mL of Ag[GE]-NPs, Ag[TO]-NPs and Ag[EF]-NPs revealed significant inhibitions of cell growth of HepG2 resulting in cell viabilities 5.92%, 4.44% and 11.33%, respectively. These findings suggest that macroalgae bio-capped Ag-NPs have magnificent biological potentials for safe biomedical applications.

More suitable wastewater treatment schemes need to be developed to get rid of harmful dyes and pigments before they are discharged, primarily from apparel and textile factories, into water bodies. Silver nanoparticles (Ag-NPs) are very effective, reductive nanocatalysts that can degrade many organic dyes. In this study, Ag-NPs are stabilized and capped with bioactive compounds such as Galaxaura elongata, Turbinaria ornata, and Enteromorpha flexuosa from marine macroalgae extracts to produce Ag[GE], Ag[TE], and Ag[EE] NPs. The reduction of Ag ions and the production of Ag[GE], Ag[TE], and Ag[EE] NPs have been substantiated by UV–Vis spectroscopy, SEM, EDX, and XRD tests. The NPs are sphere and crystalline shaped in nature with dimensions ranging from 20 to 25 nm. The biosynthesized Ag[GE], Ag[TE], Ag[EE] NPs were applied to photodegrade hazardous pigments such as methylene blue, Congo red, safranine O, and crystal violet under sunlight irradiation. In addition to the stability analysis, various experimental parameters, including dye concentration, exposure period, photocatalyst dose, and temperature, were optimized to achieve 100% photodegradation of the dyes. Moreover, the thermodynamic and kinetic parameters were calculated and the impact of scavengers on the photocatalytic mechanism was also investigated.