A novel one-step synthesis of gold nanoparticles in an alginate gel matrix by solution plasma sputtering

Abstract

We report a novel strategy to produce stable colloidal gold nanoparticles (AuNPs) in alginate aqueous solution which can be done in one step and without any chemicals. The AuNPs were produced by applying a voltage across a pair of gold electrodes which were immersed in alginate aqueous solution.Since the generation of AuNPs was caused by the sputtering of gold electrodes, the process was named the solution plasma sputtering (SPS) process. We utilize the alginate polymer in order to meet three important requirements: (1) to promote the generation of plasma in a liquid environment, (2) to endow biocompatibility to the AuNPs, and (3) to provide colloidal stability to the AuNPs-alginate aqueous suspensions. The alginate concentrations were varied as 0.2, 0.5, and 0.9 %w/v. The concentrationdependent effect on the particle size of AuNPs, the physical absorption property and the stability of the AuNPs-alginate suspensions were studied. Results indicate that preparation of chemical-free colloidal AuNPs-alginate aqueous suspension is successful by the SPS process. The obtained colloidal suspensions were stable and able to retain their strong plasmon absorption bands within a reasonable time period. As a consequence, this is a high-potential technique to produce AuNPs suspended in alginate aqueous solution appropriate for biomedical applications.

Carboxymethylagarose-AuNPs generated through green route for selective detection of Hg2+ in aqueous medium with a blue shift

“…1 shows the UV spectra of the CMA and CMA-AuNPs. The LSPR absorption maximum observed at 523 nm confirmed the formation of CMA-AuNPs (Radhakumary & Sreenivasan, 2011).The size of CMA-AuNPs obtained in the present study ranges from 5 to 7 nm and exhibited an absorption maximum at 523 nm and was in good agreement with those reported in literature (Huang & Yang, 2004b;Pal, Esumi, & Pal, 2005;Watthanaphanit, Panomsuwan, & Saito, 2014). To investigate the interaction of different metal ions with CMA-AuNPs, 100 ppm aqueous solutions of metal ions (e.g.…”

Comparative study of nanocarbons synthesized between electrodes in liquid phase by solution plasma

“…These results showed that the nanocarbons grown between electrodes appeared to be formed of stacked layers with a disordered planelike structure and the other nanocarbons formed in the liquid phase were composed of aggregations of small spheres with sizes of 15-30 nm. Comparison of sp 2 and sp 3 carbon components between BZ and BZ_C, or PD and PD_C in XPS C 1s spectra revealed that the ratio of sp 2 carbon components for BZ_C and PD_C was increased, whereas the ratio of sp 3 carbon components was decreased. BET studies demonstrated that the particle sizes of BZ_C and PD_C were much bigger than those of BZ and PD.…”

“…This result implies that the type of synthesized nanocarbon differs depending on the position of the reaction field in plasma. The ratio of sp 3 and the C-O component for PD and PD_C increased and became broader than those of BZ and BZ_C, probably affected by the doping of nitrogen atoms to the carbon matrix. A comparison of the N 1s spectra of PD and PD_C in Fig.…”

“…Electric discharge in liquid media is a versatile method for the synthesis of metal nanoparticles, [1][2][3] bimetallic nanoparticles, 4) nonmetal catalysts, [5][6][7] carbon nanospheres (CNS), 8) graphenes, 9) carbon nanotubes, [10][11][12][13] carbon onions, 14) metal nanoparticles covered by carbon, 15,16) mesoporous silica, 17) and polymers. 18) Among these, nonmetallic carbon catalysts have attracted a great deal of attention as a Pt substitute material in energy storage devices such as secondary batteries 19) and supercapacitors 20,21) for smart grids or electric automobiles.…”

Improving the performance of chitosan in the synthesis and stabilization of gold nanoparticles

“…Table 2 summarises the zeta potentials for nanoparticles synthesised at different temperatures using chitosan and its grafted copolymers. A large negative or positive zeta potential for suspended particles indicates the system is stable against flocculation or coagulation [56]. In general, the zeta potentials for gold nanoparticles prepared using grafted copolymers show a tendency to be higher compared to those synthesised with chitosan, this could indicate a better stability of nanoparticles synthesised with chitosan grafted copolymers.…”