“…We mention that sample acidity assessing has resulted in pH value of about 6 before UV irradiation and about 7.5 after irradiation. In previous studies ( Babusca et al, 2020 ) the analyzed citrate-AgNP suspensions by chemical reduction were prepared and immediately after that they were exposed to UV-C radiation (two step photochemical reduction); there we found the LSPR band intensity increasing from 0.05 after chemical reduction step to 4.5 after UV exposure step, while acidity has changed from the pH of about 5 to approximately 6; also LSPR maximum position was blue-shifted from 425 nm to 418 nm. Fig.…”
Colloidal suspensions of silver nanoparticles (AgNPs) with surface modified by capping with citrate ions were synthesized by chemical reduction method. Transmission and Scanning Electron Microscopy as well as darkfield Optical Microscopy provided information on the nanoparticle morphology, with fine symmetrical grains and log-normal fitted size distribution. Small Angle X-ray Scattering method allowed theoretical confirmation of colloidal silver nanoparticle fine granularity, based on measurements in the native fluid sample. UV–Vis spectrophotometry allowed studying the Localized Surface Plasmon Resonance band versus the stability of the citrate-AgNP sample after storage and after UV-C exposure. The colloidal AgNP impact on
Phanerochaete chrysosporium
environmental microorganisms was studied by specific biochemical investigations. Silver released from the colloidal suspension of AgNPs was supposed to induce changes in some antioxidant enzymes and in some enzymes of Krebs’ cycle. Catalase activity was moderately changed (an increase with over 50%) as well as superoxide dismutase activity, while the diminution of the activities of four dehydrogenases synthesized in the
fungus mycelium
was emphasized also: a decrease with about 60% for malate dehydrogenase, with over 50% for isocitrate dehydrogenase and succinate dehydrogenase and with about 40% for alpha-ketoglutarate dehydrogenase. These findings suggested the nano-toxicological issues of citrate-AgNPs impact on the environmental beneficial microorganisms.
“…We mention that sample acidity assessing has resulted in pH value of about 6 before UV irradiation and about 7.5 after irradiation. In previous studies ( Babusca et al, 2020 ) the analyzed citrate-AgNP suspensions by chemical reduction were prepared and immediately after that they were exposed to UV-C radiation (two step photochemical reduction); there we found the LSPR band intensity increasing from 0.05 after chemical reduction step to 4.5 after UV exposure step, while acidity has changed from the pH of about 5 to approximately 6; also LSPR maximum position was blue-shifted from 425 nm to 418 nm. Fig.…”
Colloidal suspensions of silver nanoparticles (AgNPs) with surface modified by capping with citrate ions were synthesized by chemical reduction method. Transmission and Scanning Electron Microscopy as well as darkfield Optical Microscopy provided information on the nanoparticle morphology, with fine symmetrical grains and log-normal fitted size distribution. Small Angle X-ray Scattering method allowed theoretical confirmation of colloidal silver nanoparticle fine granularity, based on measurements in the native fluid sample. UV–Vis spectrophotometry allowed studying the Localized Surface Plasmon Resonance band versus the stability of the citrate-AgNP sample after storage and after UV-C exposure. The colloidal AgNP impact on
Phanerochaete chrysosporium
environmental microorganisms was studied by specific biochemical investigations. Silver released from the colloidal suspension of AgNPs was supposed to induce changes in some antioxidant enzymes and in some enzymes of Krebs’ cycle. Catalase activity was moderately changed (an increase with over 50%) as well as superoxide dismutase activity, while the diminution of the activities of four dehydrogenases synthesized in the
fungus mycelium
was emphasized also: a decrease with about 60% for malate dehydrogenase, with over 50% for isocitrate dehydrogenase and succinate dehydrogenase and with about 40% for alpha-ketoglutarate dehydrogenase. These findings suggested the nano-toxicological issues of citrate-AgNPs impact on the environmental beneficial microorganisms.
“…The pH of the reaction medium plays an important role in controlling the size of Ag NPs [ 125 , 126 ]. Thus far, the formation of Ag NPs under UV irradiation has been limited to a narrow pH range [ 125 ].…”
Section: Synthesis Of Gold and Silver Nanoparticles Under Uv Light Irradiationmentioning
confidence: 99%
“…Some studies suggest that the Ag NP size tends to decrease in alkaline media due to the rapid nucleation, while acidic media results in larger Ag NPs since the reaction rate is slower [ 127 , 128 ]. Furthermore, the pH affects the absorption of light and the position of the localized SPR (LSPR) band [ 126 , 129 ]. Babusca et al synthesized Ag NPs via a two-step process: the aqueous mixture of AgNO 3 and trisodium citrate was heated then irradiated using a UV-C lamp (30 W) for 45 min [ 126 ].…”
Section: Synthesis Of Gold and Silver Nanoparticles Under Uv Light Irradiationmentioning
confidence: 99%
“…Furthermore, the pH affects the absorption of light and the position of the localized SPR (LSPR) band [ 126 , 129 ]. Babusca et al synthesized Ag NPs via a two-step process: the aqueous mixture of AgNO 3 and trisodium citrate was heated then irradiated using a UV-C lamp (30 W) for 45 min [ 126 ]. The two-step process promotes the efficient synthesis of Ag NPs since the reduction of silver ions is totally completed during the first step.…”
Section: Synthesis Of Gold and Silver Nanoparticles Under Uv Light Irradiationmentioning
Nanomaterials have supported important technological advances due to their unique properties and their applicability in various fields, such as biomedicine, catalysis, environment, energy, and electronics. This has triggered a tremendous increase in their demand. In turn, materials scientists have sought facile methods to produce nanomaterials of desired features, i.e., morphology, composition, colloidal stability, and surface chemistry, as these determine the targeted application. The advent of photoprocesses has enabled the easy, fast, scalable, and cost- and energy-effective production of metallic nanoparticles of controlled properties without the use of harmful reagents or sophisticated equipment. Herein, we overview the synthesis of gold and silver nanoparticles via photochemical routes. We extensively discuss the effect of varying the experimental parameters, such as the pH, exposure time, and source of irradiation, the use or not of reductants and surfactants, reagents’ nature and concentration, on the outcomes of these noble nanoparticles, namely, their size, shape, and colloidal stability. The hypothetical mechanisms that govern these green processes are discussed whenever available. Finally, we mention their applications and insights for future developments.
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