Recent developments in the use of gold and silver nanoparticles in biomedicine

Abstract

Gold and silver nanoparticles (NPs) are widely used in the biomedical research both in the therapeutic and the sensing/diagnostics fronts. Both metals share some common optical properties with surface plasmon resonance being the most widely exploited property in therapeutics and diagnostics. Au NPs exhibit excellent light‐to‐heat conversion efficiencies and hence have found applications primarily in precision oncology, while Ag NPs have excellent antibacterial properties which can be harnessed in biomaterials' design. Both metals constitute excellent biosensing platforms owing to their plasmonic properties and are now routinely used in various optical platforms. The utilization of Au and Ag NPs in the COVID‐19 pandemic was rapidly expanded mostly in biosensing and point‐of‐care platforms and to some extent in therapeutics. In this review article, the main physicochemical properties of Au and Ag NPs are discussed with selective examples from the recent literature. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Diagnostic Tools > In Vitro Nanoparticle‐Based Sensing Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Enhanced Photoluminescence of R6G Dyes from Metal Decorated Silicon Nanowires Fabricated through Metal Assisted Chemical Etching

“…Our approach could be useful for bio and chemo-sensors based on AuNPs [ 40 ] since we have demonstrated that simple drop-casting on the Ag-nanostructured substrates could strongly enhance the PL of R6G and improve the limit of detection. However, a better understanding of the observed PL enhancement of the Au-enriched substrates is required, and the performance of the substrates using different analytes should be investigated.…”

“…Substrates prepared by the deposition of Ag or Au on nanostructured, pre-patterned surfaces, either lithographically or using templates [ 15 , 37 , 38 ] to produce ordered metallic arrays, are also considered in an effort to improve uniformity over the sensor surface. Many reviews exist in the literature [ 1 , 38 , 39 , 40 ] covering different aspects.…”

“…Bimetallic Au-Ag core-shell nanostructures and dendrites [ 27 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ] have also attracted some attention since they have shown improved SEF and SERS compared to single metal Au or Ag structures [ 40 , 41 , 46 ]. The position of the plasmon resonance was controlled through the alloy composition to custom-design substrates that match the Raman excitation or the dye emission band.…”

“…Moreover, we consider the influence of Au nanoparticles (AuNPs) after simple drop-casting on the nanostructured Ag substrates. Since many biosensor protocols are developed using AuNPs [ 40 ] the combination with Ag-nanostructured substrates could lead to improved sensors.…”

Non-medicinal parts of safflower (bud and stem) mediated sustainable green synthesis of silver nanoparticles under ultrasonication: optimization, characterization, antioxidant, antibacterial and anticancer potential

“…1 Recently, AgNPs have been applied in the elds of biomedicine, pharmaceuticals, cosmetics, catalysis, textiles and optics. [2][3][4][5][6][7][8][9][10][11][12][13][14] Studies have documented that AgNPs could be physically or chemically synthesized with high yield, but physical methods require harsh conditions like high temperature, vacuum conditions, and sophisticated instruments, and chemical additives are necessary in chemical methods. [15][16][17][18][19] Obviously, these methodologies have high production costs or they may introduce toxic and dangerous chemicals, which have potential biological risks for the environment and health.…”