Synthesis of Gold Microplates Using Bovine Serum Albumin as a Reductant and a Stabilizer

Abstract

Gold microplates were synthesized in aqueous solutions by reducing HAuCl4 with the hydroxyl groups in both serine and threonine of bovine serum albumin (BSA), which is a globular protein in its native state. In this article, we systematically investigated the effects of temperature, pH value, the concentration of BSA, and ionic species on the reduction kinetics and thus the size and morphology of the final product. The optimal experimental conditions for producing uniform Au microplates include the following: an elevated temperature in the range of 55–65 °C, an acidic solution with pH ≈ 3, and in the presence of NaCl (0.14 M). We found that if any one of these parameters was deviated from the optimal condition, Au microplates would not be formed in high yields. We also found that the surfaces of the as-synthesized Au microplates were covered by a dense array of BSA bumps.

Biomimetic one-pot synthesis of gold nanoclusters/nanoparticles for targeted tumor cellular dual-modality imaging

“…BSA, a ubiquitous plasma protein with a molecular weight of 66,500 Da, is composed of 580 amino acid residues [23,24]. Due to their wide hydrophobic, hydrophilic, anionic, and cationic properties, BSA has been extensively used as a model protein in many fields including drug delivery [25], biomimetic mineralization [26], nanomaterial synthesis [27,28], surface modification and intermolecular interaction [29], etc.…”

Technical Note: Synthesis and Characterization of Anisotropic Gold Nanoparticles

“…The peaks at the longer wavelengths can be attributed to the presence of nanoplates [20]. These peaks are attributed to the anisotropic triangular shapes of the plates as each apex is expected to produce its own plasmon resonance peak [9]. The colloid colour of the Large NP sample was a light orange hue which has been identified as a characteristic of the larger Au-nanoplates [20].…”

“…There are a number of advantages to the use of Au-NPs, particularly in biological systems including the following; Au-NPs: 1) bind readily to sulfhydryl groups which allow for simple NP functionalization by the conjugation of various biomolecules and other ligands; 2) are resistant to oxidation; 3) possess surface plasmons (in some cases multiple plasmon peaks depending on their morphology) which allow the Au-NP, and hence the attached ligand/molecule to be monitored by UV-Vis spectroscopy; 4) are biocompatible; 5) are size tunable for variation in Au-NP properties; 6) are electron dense due to the high atomic number of gold, making the Au-NPs easily identifiable by analysis with electron-microscopes and 7) laser illumination of the particles results in an increase in particle temperature due to energy absorption by the surface plasmons [3,4,[6][7][8][9].…”

Bio-inspired synthesis of metal nanomaterials and applications

“…13 The interactions between metal ions and functional groups can lead to conformational changes of proteins in aqueous solution. 48 In addition, denatured protein molecules are also responsible for directing crystal growth and subsequent capping of the resulting MNMs. temperature, pH as well as the introduction of reducing agents), favour the transformation of entrapped metal into MNMs.…”