Monitoring Thiol–Ligand Exchange on Au Nanoparticle Surfaces

Kluenker, Martin; Mondeshki, Mihail; Tahir, Muhammad Nawaz; Tremel, Wolfgang

doi:10.1021/acs.langmuir.7b04015

Cited by 35 publications

(38 citation statements)

References 68 publications

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“…46−49 Recently, the introduction of additional reducing agents enabled the facile production of smaller AuNPs with a narrow size distribution and size tunability near room temperature. 50,51 The potential of further surface functionalization by ligand exchange was recently validated for alkylthiol, 52 biphenylthiol, 53 azothiol, 54 and charged thiol mixtures. 55 Based on OAm as intermediated capping agent, we herein report on a two-step protocol for independent control over AuNP core and ligand shells.…”

Section: ■ Introductionmentioning

confidence: 99%

A Versatile AuNP Synthetic Platform for Decoupled Control of Size and Surface Composition

Yang¹,

Serrano²,

Guldin³

2018

Preprint

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While a plethora of protocols exist for the synthesis of sub-10-nm gold nanoparticles (AuNPs), independent control over the size and surface composition remains restricted. This poses a particular challenge for systematic studies of AuNP structure− function relationships and the optimization of crucial design parameters. To this end, we report on a modular two-step approach based on the synthesis of AuNPs in oleylamine (OAm) followed by subsequent functionalization with thiol ligands and mixtures thereof. The synthesis of OAm-capped AuNPs enables fine-tuning of the core size in the range of 2−7 nm by varying the reaction temperature. The subsequent thiol-for-OAm ligand exchange allows a reliable generation of thiol-capped AuNPs with target surface functionality. The compatibility of this approach with a vast library of thiol ligands provides detailed control of the mixed ligand composition and solubility in a wide range of solvents ranging from water to hexane. This decoupled control over the AuNP core and ligand shell provides a powerful toolbox for the methodical screening of optimal design parameters and facile preparation of AuNPs with target properties.

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Section: ■ Introductionmentioning

confidence: 99%

A Versatile AuNP Synthetic Platform for Decoupled Control of Size and Surface Composition

Yang¹,

Serrano²,

Guldin³

2018

Preprint

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“…However, with the increasing concentration of the thiol ligands, the interaction between the unsaturated bonds and the sulfhydryl groups on the surface resulted in a slight enhancement of the exciton radiation peak and a slight redshift. The PL intensity of the deep trap increased obviously and the defect emission peak appears blueshift 33 . Consequently, the fluorescence intensity and wavelength of QDs could be adjusted by controlling the concentration of thiol ligands.…”

Section: Resultsmentioning

confidence: 99%

Regulating the Fluorescence Emission of CdSe Quantum Dots Based on the Surface Ligand Exchange with MAA

Huang

Zeng

Bai

et al. 2020

Polymers for Advanced Techs

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Cadmium selenide (CdSe) quantum dots (QDs) is a promising semiconductor and fluorescence nanocrystal with quantum size effect. To address the problem of fluorescence emission during the process of the ligand transformation of colloidal cluster CdSe QDs from nonpolar organic solvents to polar inorganic aqueous solutions, the surface ligand exchange with mercapto acetic acid (MAA) was proposed. It was attributed to the Cd‐O bond breaking and the Cd‐S bond formation. The intensity and wavelength of fluorescence emission spectra could be adjusted by controlling the concentration of MAA. The photoluminescence (PL) spectra and UV‐Vis absorption spectra of colloidal cluster CdSe QDs indicated that the electronic properties of the interface varied with the exchange of the surface ligands. Moreover, the band‐edge emission quenching occurred and the maximum redshift of the PL spectrum could reach 28 nm. The enhancement of the deep trap emission peaks of CdSe QDs appeared in 600‐900 nm region, and the maximum blue shift of the defect peak in PL spectrum could reach 80 nm with the increase concentration of MAA. The absorption spectra and PL spectra on the surface of porous alumina thin film were used to further analyze the charge separation and capture of charge carriers. This novel organic‐inorganic ligand exchange method provides an effective strategy for regulating fluorescence and electron transfer, which could be used on biological, solar cells or other practical applications.

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“…A well-known bottom-up approach is a wet reduction in the presence of a capping agent [55,57,[59][60][61][62]64]. The obtained AuNPs can be easily investigated by microscope techniques, such as transmission electron microscope (TEM), scanning electron microscope (SEM), and atomic force microscope (AFM) [98][99][100][101][102]. Capped AuNPs are prepared by using a water solution of tetrachloroauric acid as the gold precursor, a ligand molecule, and a reducing agent.…”

Section: Aunpsmentioning

confidence: 99%

“…Capped AuNPs are prepared by using a water solution of tetrachloroauric acid as the gold precursor, a ligand molecule, and a reducing agent. Functionalizations can be produced on the gold surface using different synthetic strategies: (i) the method of ligand exchange; (ii) the introduction of bifunctional thiols; (iii) the use of many different capping agents throughout the synthesis mixture; and (iv) the derivation reaction in a post-synthesis procedure [99,[103][104][105][106]. The ligand exchange is an easy and cheap mode to functionalize the gold surface, but frequently leads to a partial coverage that is short lasting and stable in time.…”

Section: Aunpsmentioning

confidence: 99%

“…The ligand exchange is an easy and cheap mode to functionalize the gold surface, but frequently leads to a partial coverage that is short lasting and stable in time. In fact, this approach is based on an equilibrium reaction associated with the Nernst distribution [99]. The use of bifunctional thiols (HS-----X), which presents a free end group X, such as thiol, acid, amine, ester, and ether, allows the particle interactions with the external environment and enhance post-synthesis modifications.…”

Section: Aunpsmentioning

confidence: 99%

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Gold Nanoparticles and Nanorods in Nuclear Medicine: A Mini Review

et al. 2019

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In the last decade, many innovative nanodrugs have been developed, as well as many nanoradiocompounds that show amazing features in nuclear imaging and/or radiometabolic therapy. Their potential uses offer a wide range of possibilities. It can be possible to develop nondimensional systems of existing radiopharmaceuticals or build engineered systems that combine a nanoparticle with the radiopharmaceutical, a tracer, and a target molecule, and still develop selective nanodetection systems. This review focuses on recent advances regarding the use of gold nanoparticles and nanorods in nuclear medicine. The up-to-date advancements will be shown concerning preparations with special attention on the dimensions and functionalizations that are most used to attain an enhanced performance of gold engineered nanomaterials. Many ideas are offered regarding recent in vitro and in vivo studies. Finally, the recent clinical trials and applications are discussed.Radiopharmaceuticals are showing amazing outcomes in diagnostic (90%) and therapeutic (10%) applications for many diseases such as cancer, heart and brain diseases, and so on [33]. They consist of a radioactive nuclide linked to a biologically active molecule directed to the target of interest. When radionuclides emit γ rays (either directly, as pure γ emitters, or indirectly, as β+ emitters), the radiopharmaceutical is intended for diagnostic imaging. When radionuclides emit β− or α particles (thanks to the cell-damaging properties) the radiopharmaceutical is used for therapeutic applications and, in some recent research studies, even for radio-guided surgery [34][35][36]. Theragnostics is a new term that implies the use of the same molecule, labeled with different radionuclides, for both diagnostic and therapeutic purposes [37][38][39].Radiopharmaceuticals have been increasingly used for medical diagnosis since the late 1940s, when nuclear medicine was born. Nuclear medicine aims at evaluating both physiological function as well as biochemical changes in disease conditions; it includes two-dimensional (2D) imaging (planar scintigraphy) and three-dimensional (3D) imaging (single-photon emission computed tomography, SPECT, and positron emission tomography, PET). The functional information obtained by SPECT and PET may need to be coupled with the anatomic/morphologic information typically provided by computed tomography (CT) (hence SPECT and PET are now commonly called SPECT-CT and PET-CT): these approaches, named "hybrid imaging", have many advantages as well as high sensitivity, good spatial resolution, and the possibility to correctly locate functional abnormalities (by the SPECT or PET component) within a definite anatomic field (by the CT component) [34].The γ-emitting radionuclides that are used for planar and SPECT imaging are usually obtained within hospital nuclear medicine facilities (or research departments) from small portable generators; some are produced by nuclear reactors and then shipped to the hospital facility ready to use. The β+ emitting radionuclides ...

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Monitoring Thiol–Ligand Exchange on Au Nanoparticle Surfaces

Cited by 35 publications

References 68 publications

A Versatile AuNP Synthetic Platform for Decoupled Control of Size and Surface Composition

A Versatile AuNP Synthetic Platform for Decoupled Control of Size and Surface Composition

Regulating the Fluorescence Emission of CdSe Quantum Dots Based on the Surface Ligand Exchange with MAA

Gold Nanoparticles and Nanorods in Nuclear Medicine: A Mini Review

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