Alginate-Stabilized Gold Nanoparticles Prepared Using the Microwave-Induced Plasma-in-Liquid Process with Long-Term Storage Stability for Potential Biomedical Applications

Abstract

A one-step preparation of alginate-stabilized gold nanoparticles (Au NPs) using the microwave-induced plasma-in-liquid process (MWPLP) was reported. Effects of alginate with various concentrations on the preparation and properties of the synthesized Au NPs, including reaction rate, morphology, size, and optical absorption property, were studied. The introduction of alginate (1) accelerated the reaction rate, (2) prevented aggregation and precipitation due to long time discharge in MWPLP, and (3) provided long-term colloidal stability. An abnormal size change (from large to small) of Au NPs during particle growth, which was opposite to the typical change in bottom-up chemical reduction, was observed and a possible mechanism was proposed based on the dynamical and thermodynamical instability of particles during growth. The strategy of drying and redispersion of Au NPs in alginate solution was also studied. The drying and redispersion process had an imperceptible effect on the Au NPs. As a consequence, this strategy might be an effective technique for the long-term storage of Au NPs and other metal NPs. The alginate-stabilized Au NPs without the addition of toxic reducing or stabilizing agents can be appropriate to biomedical applications.

Green and effective synthesis of gold nanoparticles as an injectable fiducial marker for real-time image gated proton therapy

“…The excellent biocompatibility, low toxicity, easy surface functionalization, and interactions between substances 1 of gold with different types of structures make them potential candidates in diverse biomedical fields, 2,3 including clinical diagnostics, 4,5 therapies, 6,7 biosensors, 8 and immunology. 9,10 In addition to these applications, the unique properties of gold, i.e., high atomic number, electron density, and surface plasmon resonance (SPR), also allow gold-based materials to be readily used for labelling and imaging, such as computed tomography (CT), 11,12 magnetic resonance imaging (MRI), 13 nuclear imaging, 14 optical imaging, 15 and photoacoustic imaging.…”

“…Owing to the abundant free hydroxyl and negatively charged carboxyl groups, alginate has the potential to accelerate the reaction rate and control the growth of Au NPs, which is supported by our previous work. 3 For this reason, the strategy of adding sodium alginate to the ethanol system was explored to tackle these limitations for higher efficacy and improved injectability. The reducing capacity of the ethanol system was significantly enhanced because of the introduced hydroxyl and carboxyl groups distributed along the alginate backbone.…”

“…The excellent biocompatibility, low toxicity, easy surface functionalization, and interactions between substances 1 of gold with different types of structures make them potential candidates in diverse biomedical fields, 2,3 including clinical diagnostics, 4,5 therapies, 6,7 biosensors, 8 and immunology. 9,10 In addition to these applications, the unique properties of gold, i.e.…”

Gold Tablets: Gold Nanoparticles Encapsulated into Dextran Tablets and Their pH-Responsive Behavior as an Easy-to-Use Platform for Multipurpose Applications

“… 13 − 15 Their ease of preparation, variable surface chemistry, and nano size variation make AuNPs suitable candidates for a range of applications such as food packaging, water purification, batteries, nanoceramics, and electronics. 16 − 19 One of the aspects is the surface plasmon resonance phenomenon, which is a fundamental principle of many colorimetric sensing applications. This unique feature can be tuned sharply based on the surrounding functionality and stabilization forces around nanogold as well as their interparticle distance and morphology.…”

“…These nanoparticles have shown remarkable chemical, biological, optical, thermal, and electronic characteristics. Several chemical, biological, and physical approaches have been reported for the synthesis of these nanometallic particles under mild conditions. − Their ease of preparation, variable surface chemistry, and nano size variation make AuNPs suitable candidates for a range of applications such as food packaging, water purification, batteries, nanoceramics, and electronics. − One of the aspects is the surface plasmon resonance phenomenon, which is a fundamental principle of many colorimetric sensing applications. This unique feature can be tuned sharply based on the surrounding functionality and stabilization forces around nanogold as well as their interparticle distance and morphology.…”