Minute synthesis of extremely stable gold nanoparticles

Abstract

We describe a rapid environmentally friendly wet-chemical approach to synthesize extremely stable non-toxic, biocompatible, water-soluble monodispersed gold nanoparticles (AuNPs) in one step at room temperature. The particles have been successfully achieved in just a few minutes by merely adding sodium hydroxide (NaOH) acting as an initiator for the reduction of HAuCl(4) in aqueous solution in the presence of polyvinylpyrrolidone (PVP) without the use of any reducing agent. It is also proved to be highly efficient for the preparation of AuNPs with controllable sizes. The AuNPs show remarkable stability in water media with high concentrations of salt, various buffer solutions and physiological conditions in biotechnology and biomedicine. Moreover, the AuNPs are also non-toxic at high concentration (100 microM). Therefore, it provides great opportunities to use these AuNPs for biotechnology and biomedicine. This new approach also involved several green chemistry concepts, such as the selection of environmentally benign reagents and solvents, without energy consumption, and less reaction time.

Inquiring the mechanism of formation, encapsulation, and stabilization of gold nanoparticles by poly(vinyl pyrrolidone) molecules in 1-butanol

“…However, all these properties strongly depend on the type of reducing and/or stabilizing agent used in the reaction medium, synthetic route, and reaction conditions (Alexandridis 2011;Daniel and Astruc 2004). In recent years, researchers around the globe are showing plenty of interest in the use of non-toxic chemicals and environmentally friendly solvents for synthesis of GNPs (Daniel and Astruc 2004;Goy-López et al 2010;Xian et al 2012;Zhou et al 2009). Out of various fundamental strategies, the two methods tested widely so far: (1) bottom-up and (2) top-down approach, the in situ synthesis of NPs by chemical reduction of gold ions in presence of a polymer matrix-a bottom-up technique, is an extensively used synthetic route to obtain stable GNPs in both aqueous and non-aqueous medium (Alexandridis 2011;Goy-López et al 2010;Xian et al 2012;Zhou et al 2009).…”

“…In recent years, researchers around the globe are showing plenty of interest in the use of non-toxic chemicals and environmentally friendly solvents for synthesis of GNPs (Daniel and Astruc 2004;Goy-López et al 2010;Xian et al 2012;Zhou et al 2009). Out of various fundamental strategies, the two methods tested widely so far: (1) bottom-up and (2) top-down approach, the in situ synthesis of NPs by chemical reduction of gold ions in presence of a polymer matrix-a bottom-up technique, is an extensively used synthetic route to obtain stable GNPs in both aqueous and non-aqueous medium (Alexandridis 2011;Goy-López et al 2010;Xian et al 2012;Zhou et al 2009). Soon after the pioneer work of Helcher (1718) on the synthesis of GNPs in presence of a polysaccharide, scientists and academia felt that polymers could be used as efficient stabilizing/reducing agent in the development of inorganic-organic nanostructure materials of various morphologies and sizes of ones interest (Hoppe et al 2006;Goy-López et al 2010;Xian et al 2012;Zhou et al 2009).…”

“…Out of various fundamental strategies, the two methods tested widely so far: (1) bottom-up and (2) top-down approach, the in situ synthesis of NPs by chemical reduction of gold ions in presence of a polymer matrix-a bottom-up technique, is an extensively used synthetic route to obtain stable GNPs in both aqueous and non-aqueous medium (Alexandridis 2011;Goy-López et al 2010;Xian et al 2012;Zhou et al 2009). Soon after the pioneer work of Helcher (1718) on the synthesis of GNPs in presence of a polysaccharide, scientists and academia felt that polymers could be used as efficient stabilizing/reducing agent in the development of inorganic-organic nanostructure materials of various morphologies and sizes of ones interest (Hoppe et al 2006;Goy-López et al 2010;Xian et al 2012;Zhou et al 2009). In the synthesis of metal NPs, the most commonly used polymers include poly(vinyl alcohol), poly(vinyl pyrrolidone) PVP, and poly (ethylene glycol) (Hoppe et al 2006;Goy-López et al 2010;Tripathy et al 2009;Xian et al 2012;Zhou et al 2009).…”

“…Soon after the pioneer work of Helcher (1718) on the synthesis of GNPs in presence of a polysaccharide, scientists and academia felt that polymers could be used as efficient stabilizing/reducing agent in the development of inorganic-organic nanostructure materials of various morphologies and sizes of ones interest (Hoppe et al 2006;Goy-López et al 2010;Xian et al 2012;Zhou et al 2009). In the synthesis of metal NPs, the most commonly used polymers include poly(vinyl alcohol), poly(vinyl pyrrolidone) PVP, and poly (ethylene glycol) (Hoppe et al 2006;Goy-López et al 2010;Tripathy et al 2009;Xian et al 2012;Zhou et al 2009). On the other hand, the increased interest on the use of PVP as capping/reducing/nucleating agent has been increased a lot owing to its non-toxicity, good biodegradability, excellent film forming ability and easy processability, superb stabilizing ability, mild reducing ability, and outstanding solubility in various polar solvents (Alexandridis 2011;Hoppe et al 2006;Xian et al 2012;Zhou et al 2009).…”

“…In the synthesis of metal NPs, the most commonly used polymers include poly(vinyl alcohol), poly(vinyl pyrrolidone) PVP, and poly (ethylene glycol) (Hoppe et al 2006;Goy-López et al 2010;Tripathy et al 2009;Xian et al 2012;Zhou et al 2009). On the other hand, the increased interest on the use of PVP as capping/reducing/nucleating agent has been increased a lot owing to its non-toxicity, good biodegradability, excellent film forming ability and easy processability, superb stabilizing ability, mild reducing ability, and outstanding solubility in various polar solvents (Alexandridis 2011;Hoppe et al 2006;Xian et al 2012;Zhou et al 2009). It was reported that PVP reduce gold ions to Au atom and subsequently encapsulate those metal NPs via O-atom of pyrrolidone ring (Hoppe et al 2006;Xian et al 2012;Zhou et al 2009).…”