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Download fileWater-Soluble Nitric Oxide-Releasing Gold Nanoparticles
journal contribution
posted on 2007-04-24, 00:00 authored by Mark A. Polizzi, Nathan A. Stasko, Mark H. SchoenfischThe synthesis and characterization of water-soluble nitric oxide (NO)-releasing monolayer-protected gold clusters
(MPCs) are reported. Tiopronin-protected MPCs (∼3 nm) were functionalized with amine ligands and subsequently
exposed to 5 atm of NO to form diazeniumdiolate NO donors covalently bound to the gold MPC. Diazeniumdiolate
formation conditions, NO-release, and nanoparticle stability were examined as a function of the structure of the
protecting ligand, pH, and storage time. Despite their aqueous solubility, proton-initiated decomposition of the
diazeniumdiolate-modified Tio-MPCs resulted in only modest NO-release (<0.023 μmol/mg) for short durations
(<1.5 h). To increase the NO storage capacity of gold nanoparticles, polyamine-stabilized MPCs (∼5 nm) were
synthesized with significantly enhanced NO-release properties (0.386 μmol/mg) and durations (up to 16 h). Transmission
electron microscopy, thermogravimetric analysis, nuclear magnetic resonance spectroscopy, elemental analysis, and
UV−vis spectroscopy were used to characterize both nanoparticle systems before and after NO exposure. The MPCs
represent the smallest water-soluble NO-release nanoparticles to date (3−5 nm).
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thermogravimetric analysis5 atmstorage capacitymolTransmission electron microscopygold MPCnanoparticle systemsdurationDiazeniumdiolate formation conditionsresonance spectroscopynanoparticle stabilitystorage timeUVgold nanoparticlesnm16 hdonors covalentlyform diazeniumdiolatenitric oxideamine ligands