Synthesis, functionalization and characterization of gold nanoparticles

Sholanbayeva, Zhanar
Metallic nanoparticles (NPs) with various elemental composition, size, shape and physical or chemical properties has become active field of research. Among all the metal NPs noble metal ones are receiving much attention due to their special optical properties which make them useful for different applications. Noble metal NPs have bright colors resulting from strong surface plasmon resonance absorption usually in the visible region. The colors are size and shape dependent and provide the tuning of optical properties. The optical properties of NPs are also strongly depending on the nature of the NPs surface which plays a crucial role on chemical sensing. Therefore, surface modification of NPs has become increasingly important. In this study, gold NPs were prepared in aqueous phase by seed-mediated growth method. To enhance the optical properties, surface functionalization was performed by coating NPs with silver. The coating process was achieved by chemical reduction of silver ions on NPs surface. Thickness of silver layer on the NPs were attempted to be controlled by the amount of silver salt added into NPs solution. Coating process of different types of gold NPs (rod, octahedral, star) was done by the same procedure. Moreover, this attempt yielded control over silver layer thickness on sphere, rod and octahedral shaped gold NPs, but not on branched NPs. The structure, composition and spectroscopic properties of Au-Ag core shell NPs were characterized by UV-Vis spectroscopy, Field Emission Transmission Electron Microscope (FE-TEM) and Energy-dispersive X-ray (EDX) studies, Scanning Electron Microscope (SEM), and X-Ray Photoelectron Spectroscopy (XPS). The analysis showed that all NPs studied were successfully coated with silver and promising for further explorations in sensing and imaging applications.


Synthesis of gold nanowires with high aspect ratio and morphological purity
Dertli, Elçin; Nalbant Esentürk, Emren; Ünalan, Hüsnü Emrah; Department of Micro and Nanotechnology (2012)
Metal nanoparticles have unique optical, electrical, catalytic and mechanical properties, which lead them to various applications in nanotechnology. In particular, noble metal nanowires are attracting growing attention due to their potential applications such as in opto-electronic devices and transparent conductive contacts (TCCs). There are two general approaches to synthesize nanowires: template-assisted and solution phase methods. However, these synthesis approaches have various disadvantages. For exampl...
Synthesis of germanium nanowires by vapor transport and fabrication of fully transparent flexible photodetectors
Aksoy, Burcu; Ünalan, Hüsnü Emrah; Department of Metallurgical and Materials Engineering (2012)
Nanomaterials are widely investigated by researches and because of their unique properties they have been utilized in many different devices. Nanowires are one of these materials which show deviated mechanical, chemical, physical and optical, properties from their bulk counterparts. These deviations in properties of the nanowires are based on both their high surface to volume ratio and quantum confinement effect. Lately optical properties of nanowires have received great attention as they also exhibit good ...
Preparation and surface modification of noble metal nanoparticles with tunable optical properties for SERS applications
Kaya, Murat; Volkan, Mürvet; Department of Chemistry (2011)
Metal nanostructures exhibit a wide variety of interesting physical and chemical properties, which can be tailored by altering their size, morphology, composition, and environment. Gold and silver nanostructures have received considerable attention for many decades because of their widespread use in applications such as catalysis, photonics, electronics, optoelectronics, information storage, chemical and biological sensing, surface plasmon resonance and surface-enhanced Raman scattering (SERS) detection. Th...
Use of gold nanoparticle containing poly (allylamine hydrochloride)/ poly (acrylic acid) multilayer films as sers substrates
Kölemen, Birsu; Ertaş, Gülay; Erel Göktepe, İrem; Department of Chemistry (2015)
Surface-enhanced Raman spectroscopy (SERS) is a surface sensitive vibrational spectroscopy technique that results in the enhancement of Raman scattering by molecules adsorbed on rough metal surfaces. It is a powerful, sensitive and non-destructive technique which is used in chemical, material and life sciences including biosensing, catalysis, spectroelectrochemistry, criminology, single molecule SERS applications and many others. Nanoparticle (NP) embedded multilayer films using Layer by Layer (LbL) techniq...
Synthesis, structural and magnetic characterization of soft magnetic nanocrystalline ternary FeNiCo particles
Toparlı, Çiğdem; Gürmen, Sebahattin (2017-02-01)
The present study focuses on the synthesis, microstructural and magnetic properties of ternary FeNiCo nanoparticles. Nanocrystalline ternary FeNiCo particles were synthesized via hydrogen reduction assisted ultrasonic spray pyrolysis method in single step. The effect of precursor concentration on the morphology and the size of particles was investigated. The syntheses were performed at 800 degrees C. Structure, morphology and magnetic properties of the as-prepared products were characterized through X-ray d...
Citation Formats
Z. Sholanbayeva, “Synthesis, functionalization and characterization of gold nanoparticles,” M.S. - Master of Science, Middle East Technical University, 2012.