Light emitting diode irradiation induced shape conversion of DNA-capped silver nanoparticles and their antioxidant and antibacterial activities

Abstract

Due to size- and shape-dependent properties, a shape-controlled synthesis of silver nanoparticles (AgNPs) is one of the research challenging topics for their production and potential applications. This work reported the simple eco-friendly syntheses of different shaped AgNPs controlled by the plasmid DNA content and light emitting diodes (LEDs) irradiation. The synthesized AgNPs appeared as yellow, orange and green colloidal AgNPs, which transmission electron microscope (TEM) images revealed their different shapes; spherical AgNPs, a mixture of spherical and hexagonal AgNPs, and a mixture of spherical, hexagonal and corner-truncated triangle AgNPs, respectively. The average sizes of spherical, hexagonal and corner-truncated triangle AgNPs in the green colloidal solution were 12.32 ± 2.22, 23.03 ± 6.62 and 15.84 ± 4.31 nm, respectively. The analyses of X-ray diffraction, selected area electron diffraction and high-resolution TEM indicated the crystalline nature of the synthesized particles as the face-centred cubic silver. All synthesized AgNPs exhibited antioxidant activities similarly, whereas the yellow colloidal AgNPs exhibited the strongest antibacterial activity against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus as compared with the green and orange colloidal AgNPs.

Light-Emitting-Diode-Assisted, Fungal-Pigment-Mediated Biosynthesis of Silver Nanoparticles and Their Antibacterial Activity

“…Our time course study revealed the influence of blue LED on AgNP synthesis compared with that of other light exposure treatments. Different light wavelengths induced AgNP biosynthesis in a different manner owing to variation in triggering mechanisms on diverse phytochemicals present in the bio-reducing agents [ 29 , 34 ]. Further, AgNPs are metal nanoparticles that respond to electromagnetic (EM) fields of light [ 25 ].…”

“…The report also indicated the possibility of light-assisted AgNP synthesis using a fungal extracellular pigment as a reducing and capping agent. Although the effect of LED light on the size and shape of biosynthesized AgNPs using T. purpurogenus extracellular pigments has not yet been established, there have been reports on LED light-assisted size and shape control of AgNPs using I-2959 aqueous solution [ 25 ] and salmon DNA extract combined with NaBH 4 [ 29 ]. Based on data from recent studies, different LED wavelengths might affect fungal pigment extract-mediated AgNPs biosynthesis, which can perhaps be used as a novel technique for AgNP biosynthesis.…”

Sequence Does Not Matter: The Biomedical Applications of DNA-Based Coatings and Cores

“…NPs with an average size of 61.36±10.15 nm were formed, which exhibited antibacterial activities against E. coli and S. aureus bacteria. In another study, plasmid DNA and irradiation with light emitting diodes guided the formation of differently shaped AgNP [ 114 ]. All-spherical yellow NP, synthesized under blue light irradiation and low DNA content, demonstrated higher antibacterial effect than anisotropic AgNP synthesized at larger DNA contents ( Figure 4 b,c).…”

“…UV-Vis spectra of AgNP ( b ) and TEM images (scale bar is 50 nm) ( c ) of AgNP obtained under blue light and different DNA content (left–10 µg, middle–20 µg, right–40 µg). Reproduced with permission from [ 114 ]. Copyright 2018 Taylor & Francis.…”

Combination of AgNPs and Domiphen is Antimicrobial Against Biofilms of Common Pathogens

“…Generally, different physical and chemical methods are employed for the synthesis of AgNPs, 17 such as chemical reduction, 18 photochemical reduction, 19 electro-irradiation, 20 ultraviolet (UV) irradiation 21 and laser-mediated synthesis. 22 However, most techniques used for the synthesis of AgNPs are expensive or have adversely affect the environment and biological systems.…”