Facile preparation of size-controlled gold nanoparticles using versatile and end-functionalized thioether polymer ligands

Abstract

At present, thiol ligands are generally used whenever the classical Brust-Schiffrin two-phase method is employed to prepare metal nanoparticles. In general, the previous research was mainly focused on utilizing small molecular thiol compounds or thiol polymers as the stabilizers in organic phase to obtain small sized and uniform gold nanoparticles (Au NPs). Such preparations are usually associated with the problems of ligand exchange on the nanoparticle's surface due to strong Au-thiol interaction. Herein, we report an approach to produce fairly uniform Au NPs with diameters about 2-6 nm using thioether end-functional polymer ligands (DDT-PVAc and PTMP-PVAc) as the capping agents. These nanoparticles are thoroughly characterized using DLS, TEM, UV-Vis spectroscopy and other complementary techniques. The results indicate that multidentate thioether polymeric ligands (PTMP-PVAc) lead to formation of smaller but special 'multimer' morphology in organic phase; whereas fairly uniform nanoparticles are produced using monodentate thioether functionalized ligands (DDT-PVAc). Further modification of such polymer ligands to introduce the hydrophilic functionalities realizes the phase transfer of Au NPs from organic to aqueous media.

Surface engineered antifouling optomagnetic SPIONs for bimodal targeted imaging of pancreatic cancer cells

“…32 These sulfhydryl compounds can act as multidentate ligands that replace the original ones on some hydrophobic nanoparticles via ligand exchange. [33][34][35] Based on the unique structure of BSA, it was found that the QDs were effectively surface functionalized under ultrasonication. 21 However, SPIONs were found to cluster at an average size of 100 nm.…”

Following the Thermal Activation of Au25(SR)18 Clusters for Catalysis by X-ray Absorption Spectroscopy

“…38,1−5 However, this strong bonding is also believed to passivate the surface of Au and hence leaves little surface area available for the catalysis to take place. 40,41 This problem can be addressed to some extent by either decreasing the size of the Au MPCs or by using less bulky thiol stabilizers. 6,11 In our previous study we showed that the catalytic activity of thiolate protected Au MPCs for the reduction catalysis of 4-nitrophenol was dependent on the chain length of the thiolate and found that Au 25 (SC 8 H 9 ) 18 MPCs had the highest catalytic activity while Au 25 (SC 12 H 25 ) 18 MPCs showed the lowest activity.…”

Effective Reduction of Nonspecific Binding by Surface Engineering of Quantum Dots with Bovine Serum Albumin for Cell-Targeted Imaging

“…[22][23][24][25]36,37 However, there have been few reports on the possibility of -S-S-groups being responsible for original organic ligand exchange on the surface of QDs. In this study, the following experiment was conducted to address this issue.…”