Simple synthesis of gold-decorated silica nanoparticles by in situ precipitation method with new plasmonic properties

Abstract

We describe a simple method for the preparation of gold-decorated silica (SiO2) nanoparticles (NPs) by the in situ precipitation method using simple BH4− ions reduction as a procedure, where BH4− ions are adsorbed onto PEI-functionalized SiO2 NPs for stabilizing and reducing gold ions onto PEI-SiO2 surface in water under ambient conditions. The result was 3-nm gold nanoshell NPs attached to SiO2 core (~ 75 nm) with a surface plasmon resonance (SPR) at ~ 680 nm. SPR band is associated with Au NP aggregates that arise from strong interparticle interaction. This is an alternative to the gold-seeding methods and the use of anionic gold species for the obtention of gold-decorated SiO2 NPs with an important red-shift in UV–Vis absorption and with potential applications in biosensors and photothermal therapy.

Investigation of different deposition methods for synthesized gold nanoparticles on a South African sugarcane leaves derived silica xerogel support

“…Out of the mentioned noble metal nanoparticles, gold nanoparticles are however the most researched due to the fact that at its nanoscale, gold is the most stable noble metal [1]. The synthesis of gold nanoshells with various dimensions and shapes presents the possibility of acquiring metallic nanoshells that consists of a surface plasmon resonance band located in the near-infrared range [3]. Gold nanoparticles have been reported to be involved in many major chemical transformations such as the oxidation of hydrocarbons and alcohols [4], redox reactions, dehydrogenation and hydrogenation reactions [5].…”

“…Gold nanoparticles have been reported to be involved in many major chemical transformations such as the oxidation of hydrocarbons and alcohols [4], redox reactions, dehydrogenation and hydrogenation reactions [5]. Other applications of gold nanoparticles are in the field of biomedical imaging, biosensors, fluorescent sensors, photothermal therapy, drug carriers for cancer treatment [3]. According to Min and Friend [6], their catalytic properties are directly affected by particle size and morphology.…”

An Overview of Current and Prognostic Trends on Synthesis, Characterization, and Applications of Biobased Silica

“…Te most common applications of liquid silicates are found in the development of ceramics [25,26], concrete materials [27], glasses manufacturing [28], cement [29], delivery of biologically active ions [30], supercapacitors manufacturing [31], batteries [32], pharmaceuticals and cosmetics [33], detergents and adhesive agents [3,4,34]. Solid-state silica is used for various applications in the manufacturing of petroleum-derived products [35], fne-chemicals [36], biofuels [37], oil recovery [38], pollution abatement technologies and optical materials [4,39], catalyst support [40], microflters [41], thermal superinsulation [42], controlled release of drugs [23], and drug delivery systems for antibiotics [34,43].…”

Synthesis of Bifunctional Magneto-Plasmonic Fe₃O₄@SiO₂–Au Nanoparticles by an Ultrasound-Assisted Chemical Method

“…[1][2][3][4][5][6][7][8][9][10] In bifunctional magneto-plasmonic Fe 3 O 4 @SiO 2 @Au (FSA) nanoparticles, the Au/Fe 3 O 4 ratio plays important role in determining the contrast enhancement of computed tomography (CT) images, SERS enhancement, and determining photothermal properties. [4][5][6][7]11) In general, the higher the Au/Fe 3 O 4 ratio, the stronger the CT contrast enhancement because the presence of gold nanoparticles (Au NPs) on the surface of Fe 3 O 4 nanoparticles enhances the X-ray attenuation and thus the CT contrast. The Au NPs attached to the surface of Fe 3 O 4 nanoparticles can enhance the electromagnetic, leading to higher SERS enhancement.…”