Facile-one pot-green synthesis, antibacterial, antifungal, antioxidant and antiplatelet activities of lignin capped silver nanoparticles: A promising therapeutic agent

The current work portrays the green synthesis of Lignin Capped Silver Nanoparticles (LCSN) and their antibacterial, antifungal, antioxidant and antiplatelet potential. The LCSN was synthesized in water using a carbohydrate based polymer ‘lignin’ as the reducing and capping agents. The peak at 406nm (λmax) in the UV–Vis., spectrum and EDX analysis confirmed 1.68% (w/w) of silver was found to be loaded on lignin. The characteristic sharp peaks appeared in the PXRD spectrum showed fcc crystalline structure LCSN. SEM and TEM images indicated that the spherical Ag-NPs were well dispersed on lignin with an average particle size of ~10–15nm. LCSN showed antibacterial and antifungal activity against human pathogens S. aureus, E. coli and A. niger and the percentage of zone of inhibition was found to be 10%, 12% and 80% respectively. Further, LCSN was evaluated for antioxidant potential using DPPH scavenging assay, interestingly it showed antioxidant activity and the percentage against positive control vitamin C was found to be 70%. Furthermore, LCSN did not interfere in plasma coagulation; however, it found to inhibit agonist ADP induced platelet aggregation of human platelet rich plasma. The observed inhibition was found to be 37% and the calculated IC50 value was found to be 9mg/mL. LCSN did not lyses RBC membrane when assayed hemolytic activity suggesting its non-toxic nature. [Display omitted] •Silver nanospheres with an average size of 10-15nm were synthesized first time in water and stabilized by lignin.•Lignin is a cheap, naturally abundant, non-toxic, biodegradable, environmentally benign and flexible biopolymer.•Lignin Capped Silver Nanoparticles (LCSN) was well characterized by UV-Vis., FT-IR, SEM, TEM, EDX, and PXRD.•LCSN found a potential antibacterial, antifungal, antioxidant and antiplatelet activity.