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Recent efforts to develop biocompatible and environmentally-friendly nanomaterials have yielded many biosynthetic methods for producing metallic nanoparticles which employ organisms from almost every branch of life. However, little progress has yet been made regarding the underlying mechanisms of most of these biosynthetic methods. In an attempt to address this gap in a knowledge, we have investigated the nanoparticle-producing ability of the ubiquitous biomolecule nicotinamide adenine dinucleotide (NADH), and have found that this coenzyme alone is sufficient to reduce Au3+ ion to gold nanoparticles (GNPs) in vitro. Synthesis using this method occurs nearly instantaneously at room temperature and produces uniformly spherical plasmonic nanoparticles with small sizes (<10 nm diameter). Both the speed of synthesis and the monodispersity of the produced GNPs are advantages over many other biosynthetic methods. As NADH is a universal component of all living things, our finding also suggests that this coenzyme may contribute to - or be wholly responsible for - some of the many previously- reported syntheses of GNPs by biological systems.
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Poly (Vinyl Alcohol) Assisted Synthesis and Anti-Solvent Precipitation of Gold Nanoparticles
Gold nanoparticles (GNPs) are commonly synthesized using the Turkevich method, but there are limitations on the maximum concentration of gold nanoparticles that can be achieved using this method (often < 1 mM (=0.34 mg/mL) gold precursor loading). Here, we report an inverse Turkevich method which significantly increases the concentration of gold nanoparticles (up to 5-fold) in the aqueous phase by introducing poly (vinyl alcohol) (PVA) to the synthesis system for stabilization. The aim of this study is to understand the effect of PVA and other synthesis parameters, such as trisodium citrate and tetrachloroauric acid concentration, with the goal of maximizing concentration while maintaining gold nanoparticle morphology, stability, and narrow size distribution. The size distribution of GNPs is investigated for a range of parameters by dynamic light scattering and electron microscopy, and ultraviolet-visible (UV–vis) spectroscopy is also utilized to explore the localized surface plasmon resonance (LSPR). Further, the interaction between GNPs and PVA is investigated by Fourier-transform infrared spectroscopy. In addition to increasing the gold loading by varying synthesis parameters, we also develop a novel anti-solvent precipitation method for the PVA-coated GNPs, which enables continuous condensation and purification of GNPs by forming a gold/PVA nanocomposite.
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- PAR ID:
- 10298209
- Date Published:
- Journal Name:
- Nanomaterials
- Volume:
- 10
- Issue:
- 12
- ISSN:
- 2079-4991
- Page Range / eLocation ID:
- 2359
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/nano10122359
