Antioxidant Activities of Photoinduced Phycogenic Silver Nanoparticles and Their Potential Applications

Abstract

While various methods exist for synthesizing silver nanoparticles (AgNPs), green synthesis has emerged as a promising approach due to its affordability, sustainability, and suitability for biomedical purposes. However, green synthesis is time-consuming, necessitating the development of efficient and cost-effective techniques to minimize reaction time. Consequently, researchers have turned their attention to photo-driven processes. In this study, we present the photoinduced bioreduction of silver nitrate (AgNO3) to AgNPs using an aqueous extract of Ulva lactuca, an edible green seaweed. The phytochemicals found in the seaweed functioned as both reducing and capping agents, while light served as a catalyst for biosynthesis. We explored the effects of different light intensities and wavelengths, the initial pH of the reaction mixture, and the exposure time on the biosynthesis of AgNPs. Confirmation of AgNP formation was achieved through the observation of a surface plasmon resonance band at 428 nm using an ultraviolet-visible (UV-vis) spectrophotometer. Fourier transform infrared spectroscopy (FTIR) revealed the presence of algae-derived phytochemicals bound to the outer surface of the synthesized AgNPs. Additionally, high-resolution transmission electron microscopy (HRTEM) and atomic force microscopy (AFM) images demonstrated that the NPs possessed a nearly spherical shape, ranging in size from 5 nm to 40 nm. The crystalline nature of the NPs was confirmed by selected area electron diffraction (SAED) and X-ray diffraction (XRD), with Bragg’s diffraction pattern revealing peaks at 2θ = 38°, 44°, 64°, and 77°, corresponding to the planes of silver 111, 200, 220, and 311 in the face-centered cubic crystal lattice of metallic silver. Energy-dispersive X-ray spectroscopy (EDX) results exhibited a prominent peak at 3 keV, indicating an Ag elemental configuration. The highly negative zeta potential values provided further confirmation of the stability of AgNPs. Moreover, the reduction kinetics observed via UV-vis spectrophotometry demonstrated superior photocatalytic activity in the degradation of hazardous pollutant dyes, such as rhodamine B, methylene orange, Congo red, acridine orange, and Coomassie brilliant blue G-250. Consequently, our biosynthesized AgNPs hold great potential for various biomedical redox reaction applications.

Silver/Graphene Oxide Nanostructured Coatings for Modulating the Microbial Susceptibility of Fixation Devices Used in Knee Surgery

“…According to specialized data (PDF no. 00-004-0783) and compliant with previous studies [ 45 , 46 ], diffraction maxima at 2θ values of ~38°, ~44°, ~64°, and ~78° were assigned to the (1 1 1), (2 0 0), (2 2 0), and (3 1 1) crystallographic planes of face-centered cubic crystallized Ag.…”

“…According to specialized data (PDF no. 00-004-0783) and compliant with previous studies [45,46], diffraction maxima at 2θ values of ~38°, ~44°, ~64°, and ~78° were assigned to the (1 1 1), (2 0 0), (2 2 0), and (3 1 1) crystallographic planes of face-centered cubic crystallized Ag. The thermal behavior of the metallic powder was evaluated by correlating mass variations and thermal effects recorded by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively.…”

Antibacterial hierarchical surface fabricated using nanoimprint lithography

“…A strong peak at 3 keV is associated with the optical absorption band of Ag nanocrystallites. 36 Thus, EDS analysis of the sample confirmed the presence of Ag. 18 EDS mapping images can also be used to confirm that the PVDF-HFP/Ag with hierarchical structures has Ag ions uniformly distributed within the sample.…”

Ericaria amentacea Algae Extracts: A Sustainable Approach for the Green Synthesis of Silver Oxide Nanoparticles and Their Effectiveness against Leishmaniasis

“…The presence of a high-intensity peak at the (111) plane suggests that the nanoparticles exhibit a preferred growth orientation in that direction. Furthermore, this peak indicates the highly crystalline nature of the synthesized nanoparticles [30][31][32]. Figure 4 displays the XRD patterns of the four silver oxide nanoparticles synthesized using the environmentally friendly method: Ea-AgNPs-A, Ea-AgNPs-B, Ea-AgNPs-C, and Ea-AgNPs-D.…”