Search results for " Gold"

Birth of the Localized Surface Plasmon Resonance in Monolayer-Protected Gold Nanoclusters

2013

Gold nanoclusters protected by a thiolate monolayer (MPC) are widely studied for their potential applications in site-specific bioconjugate labeling, sensing, drug delivery, and molecular electronics. Several MPCs with 1-2 nm metal cores are currently known to have a well-defined molecular structure, and they serve as an important link between molecularly dispersed gold and colloidal gold to understand the size-dependent electronic and optical properties. Here, we show by using an ab initio method together with atomistic models for experimentally observed thiolate-stabilized gold clusters how collective electronic excitations change when the gold core of the MPC grows from 1.5 to 2.0 nm. A …

Reāllaika analīzes funkcionalitātes izstrāde datu noliktavai

2019

Šī maģistra darba mērķis ir izstrādāt reāla laika datu noliktavas arhitektūru un realizēt tai atbilstošu risinājumu kā koncepta pierādījumu. Darba ietvaros ir īsumā aprakstītas tipiskas datu noliktavas un pamatota reāla laika datu noliktavu nepieciešamība. Darba turpinājumā tika apkopota pieejamā akadēmiskā informācija par metodēm, kuras var izmantot, reāla laika datu noliktavu izstrādē. Darbā ir sniegts augsta līmeņa eksistējošās statiskās datu noliktavas apraksts, kā arī detalizēts reāla laika analīzei pielāgoto datu noliktavas izpildes pamatrādītāju ETL process. Turpinājumā ir detalizēti aprakstīta izstrādātā reāla laika risinājuma arhitektūra un tā izstrādes process, izmantojot rīku Ora…

Enhanced Efficiency of Organic Solar Cells by Thiol-capped Au-Nanoparticles

2015

In this work, we present a study on the effect of thiol-capped AuNPs of various sizesin an organic solar cell.AuNPs have been obtained by laser ablation in liquid solution[2], have been functionalized both with 2-naphthalenethiol and alkanethiol having different length. In addition to bulk heterojunction structures with optimized interpenetrating network of donors and acceptor domains, we have chosen to study planar heterojunctions (PHJs), consisting of three component thin films realized by sequential deposition of P3HT, AuNPs and PCBM from orthogonal solvents.

Selective and sensitive colorimetric detection of the neurotransmitter serotonin based on the aggregation of bifunctionalised gold nanoparticles

2018

[EN] We report a simple, sensitive and selective method for the colorimetric detection of serotonin (5-HT) in aqueous media using bifunctionalized gold nanoparticles (AuNPs). The probe (1) consisted of AuNPs functionalised with dithiobis(succinimidylpropionate) (DSP) and N-acetyl-l-cysteine (NALC). DSP was chosen to react with the amino group of 5-HT, whereas NALC was chosen to bind the hydroxyl group in 5-HT through hydrogen bonding and electrostatic interactions. A double interaction between nanoparticles and the hydroxyl and the amino group of serotonin led to interparticle-crosslinking aggregation. This, resulted in a colour change from red to blue that can be observed by the naked eye.…

Colorimetric detection of normetanephrine, a pheochromocytoma biomarker, using bifunctionalised gold nanoparticles.

2019

[EN] A simple and effective colorimetric method for the detection of normetanephrine (NMN), an O-methylated metabolite of norepinephrine, using functionalised gold nanoparticles is described. This metabolite is an important biomarker in the diagnosis of adrenal tumours such as pheocromocytoma or paraganglioma. The colorimetric probe consists of spherical gold nanoparticles (AuNPs) functionalised with two different ligands, which specifically recognize different functional groups in normetanephrine. Thus, a benzaldehyde-terminated ligand was used for the recognition of the amino alcohol moiety in NMN, by forming the corresponding oxazolidine. On the other hand, N-acetyl-cysteine was chosen f…

New amphiphilic copolymers based on a poly(hydroxyethylaspartamide): coating of Au nanostars to obtain antimicrobial photothermal/delivering systems …

2012

Gold nanoparticles induce cytotoxicity in the alveolar type-II cell lines A549 and NCIH441.

2009

Abstract Background During the last years engineered nanoparticles (NPs) have been extensively used in different technologies and consequently many questions have arisen about the risk and the impact on human health following exposure to nanoparticles. Nevertheless, at present knowledge about the cytotoxicity induced by NPs is still largely incomplete. In this context, we have investigated the cytotoxicity induced by gold nanoparticles (AuNPs), which differed in size and purification grade (presence or absence of sodium citrate residues on the particle surface) in vitro, in the human alveolar type-II (ATII)-like cell lines A549 and NCIH441. Results We found that the presence of sodium citra…

Conoscenza e percezione: epistemologie cognitiviste e naturalizzazione del relativismo

2010

Photosensitised Seeding of Thiolate-Stabilised Gold Nanoparticles

2010

Enhancement of visible light photoelectrocatalytic activity of ZnO(core)/TiO2(shell) composite by N-doping and decorating with Au0 nanoparticles

2017

Abstract The composites consisting of ITO-supported ZnO nanorods covered with TiO2 shell were doped with nitrogen and decorated with gold nanoparticles in order to improve their photocatalytic activity under visible light. N-doped TiO2 (TiO2(N)) was prepared under mild conditions through a simple sol-gel synthesis in the presence of NH4Cl. Such procedure results in formation of a highly porous shell of TiO2(N) on the ZnO nanorods. The gold nanoparticles (AuNPs) of the size 7–25 nm were grafted onto the surface of TiO2 as well as TiO2(N) by a photodeposition method from aqueous solution of [AuCl(4-x)(OH)x]− precursor at pH 6.7. The composition and microstructure of the prepared samples were …