Stabilization of PbS Nanocrystals by Bovine Serum Albumin in its Native and Denatured States

Abstract

PbS nanocrystals (NCs) are synthesized in aqueous phase within a temperature range of 40–80 °C in the presence of native and denatured states of bovine serum albumen (BSA) as the capping/stabilizing agent. The NCs are characterized with the help of field‐emission scanning electron microscopy, high‐resolution transmission electron microscopy, X‐ray diffraction, and energy‐dispersive X‐ray analysis. At 40 °C, large ball‐shaped NCs (145 ± 37 nm) with small surface protrusions are formed when 1 × 10−4 g mL−1 BSA is used. As the reaction temperature is increased towards 80 °C, the size of NCs decreases and they acquire somewhat cubic geometries (49.1 ± 7.0 nm) due to a change in the capping behavior of BSA between its native and denatured states. The native and denatured states of BSA are simultaneously studied by fluorescence spectroscopy using tryptophan emission, and pH measurements with respect to time and temperature. Gel electrophoresis is used to determine the polarity of the BSA capped NCs. Only the small sized NCs conjugated with relatively larger amounts of BSA show a displacement towards the positively charged electrode in comparison to larger NCs with lower amounts of BSA capping. It was concluded that the denatured state of BSA is more effective in controlling the crystal growth of PbS than its native state especially in the low concentration range.

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.…”

Influence of morphology in the catalytic activity of bioconjugated platinum nanostructures

“…The interactions between protein and nanoparticles do not poison the whole surface of the metallic entity, as we have shown in the concentration-dependent suppression of the biological activity of virus HIV-1 (Elechiguerra et al 2005). BSA protein has also been widely used as stabilizing agent for nanomaterials (Bakshi et al 2009;Bunker et al 2007;Meziani et al 2005;Shang et al 2007). Interestingly, shape-control of platinum nanoparticles using BSA as capping agent has not been reported.…”

“…BSA is a globular protein consisting of a single polypeptide chain with 583 amino acid residues, and its ability to form complexes with different noble-metal nanoparticles has been studied previously with silver (Elechiguerra et al 2005), gold (Burt et al 2004), platinum (Burt 2007), and others (Bakshi et al 2009). The interactions between protein and nanoparticles do not poison the whole surface of the metallic entity, as we have shown in the concentration-dependent suppression of the biological activity of virus HIV-1 (Elechiguerra et al 2005).…”

Hybrid Materials for Integrated Photonics

“…As their absorption and emission wavelength depend on the dot size, which can easily be controlled during synthesis, they are extremely attractive as building blocks for nanophotonic applications. Nowadays, they have found a wide range of potential applications in biosensors, chemical sensors, photovoltaic cells, light amplifiers, and light emitting diodes [33,34]. Recently, it was also demonstrated that such materials have also a large nonlinear refractive index 2 at telecom wavelengths, which raises a large interest in their possible application as nonlinear optical materials for photonics (e.g., like for optical switching, holography gratings, and spectral filtering).…”

“…For the near-infrared spectral range, lead-based colloidal QDs are of considerable interest due to their unique optical and electronic properties [33,34]. Their absorption and emission wavelengths depend on the dot size, which can be easily controlled during chemical synthesis.…”