Abstract

Surface-functionalized nanodiamond (ND) is a promising material for nanomedicine and nanotechnology applications. Among the surface functionalizations developed for ND, thiol-termination has received relatively little attention. Here we describe a new method of thiolating the surface of detonation and high-pressure high-temperature ND by treatment with elemental sulfur at 450 °C, followed by reduction of surface-bound sulfur moieties. The surface composition of the functionalized ND was characterized using X-ray photoelectron spectroscopy and transmission electron microscopy. Analysis revealed the presence of both sulfur in the thiol oxidation state and oxygen, indicating that the surface was partially modified with thiols with no graphitization of the diamond surface detected. The surface thiols participated in a thiol-Michael addition with fluorescein-5-maleimide, demonstrating the utility of the thiols for conjugation of molecules to the diamond surface. Thiolated detonation ND was used as a support for gold (Au) nanoparticles (NPs) formed by in situ reduction of Au salt at 250 °C. The thiol-terminated ND stabilized the Au NPs, maintaining the small (~4 nm) size, whereas aggregates formed on ND powder with an oxygenated surface. The supported Au NPs catalyzed the reduction of resazurin, indicating that the active sites were not passivated by interaction with the ND surface thiols.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.