Characterization, biological activity and photodegradation efficacy of synthesized tryptophan capped silver nanoparticles

Tryptophan capped Silver nanoparticles (AgNPs) were synthesized through a sonochemical method, utilizing tryptophan as a biocompatible and non-toxic capping agent. Based on UV–visible spectra, the optical band gap of the nanoparticles was found to be roughly 3.01 eV. The TEM and XRD measurements of the particle sizes showed a range of 10–22 nm. Under sun irradiation, these nanoparticles showed notable photocatalytic activity, destroying Methylene Blue (MB) dye by more than 79.4 %. With a pseudo-first-order apparent rate constant of 1.5×10⁻²min-1, the degradation kinetics were observed. The photocatalysis of MB dye was investigated using liquid chromatography in conjunction with electrospray ionization time-of-flight mass spectrometry (LC-ESI-TOF-MS) to determine the products generated and to clarify the degradation processes. Additionally, the antibacterial, anticancer potential showed thate the nanoparticles exhibited good antibacterial and notable anticancer properties. Furthermore, the antidiabetic activity was investigated through α-glucosidase inhibition, demonstrating a significant inhibition rate of 53.98 %. Antioxidant capabilities were also tested using ABTS and DPPH assays, revealing antioxidant activities of 73.9 % and 52.04 %, respectively. Overall, the synthesized tryptophan-capped AgNPs show promising applications in environmental remediation, as well as potential therapeutic uses.