Gold Bulletin最新文献

Utilizing the full potential linearized augmented plane wave and local orbitals (FP-LAPW + lo), the structure, electronics, optical, elastic as well as transport characteristics of A₂LaAuCl₆ (A = K, Rb or Cs) were computed by using density functional theory (DFT). The electronic band structure of the Halide double perovskites (HDPs) A₂LaAuCl₆ (A = K, Rb, or Cs) suggested the presence of indirect and wide band gaps in these compounds. The energy band gaps of such material decreased by replacing the cations from K to Rb to Cs (3.046 eV, 3.019 eV, and 2.912 eV). Strong p-d hybridization is observed in the compounds. Due to its wide bandgap nature, the compounds reveal prominent optical structures in the UV energy range. A₂LaAuCl₆ (A = K/Rb/Cs) compounds have an elastically anisotropic nature, as indicated by their estimated shear anisotropy values of 0.26, 0.61, and 0.31, correspondingly. The compounds appear to be inherently ductile based on their estimated Poisson ratios of 0.37, 0.32, and 0.37. P-type conduction is shown by the Seebeck coefficient values for A₂LaAuCl₆ (A = K/Rb/Cs), the estimated Seebeck coefficient at 800 K, which are 148 µV/K, 152 µV/K, and 141 µV/K, correspondingly. ZT values for such A₂LaAuCl₆ (A = K/Rb/Cs) compounds are (0.53, 0.54, and 0.47) at the 800 K temperature. The results of the computations serve as the basis for providing new data on A₂LaAuCl₆ (A = K/Rb/Cs) and have practical relevance for high-frequency devices.

Conventional cancer therapies face high costs and adverse effects, driving interest in natural compounds like quercetin for their therapeutic potential. However, quercetin’s poor solubility limits its effectiveness, necessitating innovative delivery methods. This study introduces a one-pot synthesis technique for quercetin-functionalized silver (Q-AgNPs) and quercetin-functionalised gold nanoparticles (Q-AuNPs), using quercetin (Q) exhibits bifunctional capabilities, operating as a potent electron donor and an effective stabilizing agent. Characterization using UV–visible spectroscopy, X-ray diffraction (XRD), FTIR spectroscopy, nanoparticle tracking analysis (NTA), and high-resolution TEM (FEG-TEM) confirms the successful creation of highly crystalline, uniform Au and Ag nanoparticles averaging 28 nm and 32 nm in diameter. Quercetin-functionalized nanoparticles show superior antioxidant, antibacterial, and anticancer properties compared to quercetin. Quercetin silver nanoparticles demonstrate significant activity against human cervical (SiHa) and colon (HT-29) cancer cell lines and effective antimicrobial activity. At low concentrations (80 µg/mL), these nanoparticles achieve a 50% reduction in cell growth. Moreover, Q-AgNPs exhibit better antioxidant activity than quercetin and (Q-AuNPs). This synthesis method offers a cost-effective, environmentally sustainable alternative, positioning quercetin-functionalized metal nanoparticles as a promising avenue for further cancer research and therapeutic development.

Our investigation explores the complex interplay between electromagnetic field and heat transfer during the fusion process of pure gold within an induction crucible furnace through a 2D-axisymmetric model. By constructing this model, we analyze the critical warm-up phase-a period marked by substantial power requirements and extended duration. This research seeks to illuminate how various geometrical and physical parameters influence the distribution of physical fields throughout the transient heating interval. Of particular interest is the path to achieving optimal melting conditions, given the intricate coupling between electromagnetic and thermal phenomena, both of which exhibit significant nonlinear characteristics. To address these challenges, we developed a computational framework based on finite volume discretization to numerically solve the governing equations of electromagnetic and heat conduction.

Synthesis of gold nanoparticles (AuNPs) in the presence of three different liquid mediums was carried out using ns-pulsed laser ablation in liquid: DDDW, NaOH, and DMEM. X-ray diffraction (XRD), atomic force microscopy (AFM), transmission electron microscopic investigations (TEM), Fourier transform infrared (FTIR), and UV–visible spectroscopy were some of the techniques that were utilized in order to describe the structural, chemical, morphological, topological, and optical features of as-produced nanomaterials. The characterization studies provided evidence that the successful synthesis route was appropriate. It has been demonstrated via the utilization of cytotoxicity tests that gold nanoparticles have the capacity to not only eradicate cancer cells but also stop their reproduction. This ability was demonstrated by gold nanoparticles. The Au nanoparticles showed an extraordinarily deadly efficacy against cancer cells as compared to cancer cells that had not been treated with the chemical. This was accomplished by preventing the growth and reproduction of cancer cells.

The Indian gold jewellery industry boasts a rich identity of the nation’s cultural, traditional, and economic heritage. Currently, the industry is facing several challenges like the high gold prices and limited arability of design flexibility manufactured using the traditional jewellery manufacturing process. In this paper, several gold jewellery manufacturing processes have been discussed such a traditional manufacturing process and lost wax casting process highlighting their limitations in terms of material waste and design constraints. The paper compares this process and proposes an idea to implement binder jet 3D printing as a disruptive innovation to revolutionize the industry. The concept of binder jet 3D printing technology was introduced explaining its core principles and emphasizing its advantages for jewellery production. The study also examines customer preferences and contemporary design trends in the context of the Indian gold jewellery sector, which would be helpful to determine that there are potential uses for binder jet 3D printing to meet the needs of current design and mass customization trends. In this paper, a model for combining traditional Indian goldsmithing methods with binder jet 3D printing is proposed. This article provided an initial plan to introduce this process in the Indian market and prepare the path for a “Digital Goldsmith” era in the Indian jewellery sector by opening doors for future research in domains, like developing eco-friendly binders and optimizing printing settings for Indian gold alloys. It imagines a world in which this thriving industry will flourish due to sustainability, innovation, and the blending of old-world artisanry with innovative technology.

Gold nanoparticle-based colorimetric detection of Hepatitis C virus (HCV) holds significant promise as a potential gold standard assay for early diagnosis and prognosis. Despite notable advancements in this field, a critical limitation persists in stabilizing gold nanoparticles (Au NPs) for extended periods, hindering their application in point-of-care devices. While polymeric capping has been frequently employed to enhance Au NP stability, its impact on the performance of colorimetric detection assays remains underexplored. In this study, we have analyzed the effect of polymeric stabilizing agents, such as polyvinyl alcohol (PVA) and polyethylene glycol (PEG) on the colorimetric detection of HCV. Additionally, we have evaluated the feasibility of using commercially available Au NPs for the assay. The findings revealed that PVA and PEG significantly improve molecular stability and shelf life of Au NPs. However, the interaction between synthetic oligomers and Au NP surfaces, influenced by the polymeric chelators, altered the biochemical properties, leading to variations in the assay’s ability to distinguish between positive and negative HCV samples. This preliminary investigation highlights the dual impact of polymeric chelators in enhancing Au NP stability and influencing assay performance. Future optimization is required to fully leverage their potential in meeting the standards for reliable colorimetric detection.

Identifying ternary gold alloys by their mere colors appears to be problematic. Surface state induces multiple reflections and creates mixtures of structural colors. Two models stochastic backward raytracing (SBR) and finite asymmetrical dihedral facets (FADF) are explored to compute the color of a given surface state. Assaying gold by its color without a touchstone seems hopeless but using colorimetric microscopy and variable magnification could be a way forward.

Peptide modification enhances the physicochemical properties of peptides by introducing specific chemical groups or structural adjustments, but achieving site-selective modification remains a significant challenge. Recently, the selective functionalization of peptides, particularly through metal catalysis, has attracted growing attention. Gold catalysts, in particular, have emerged as a powerful tool due to their high catalytic efficiency, exceptional stability, and biocompatibility. Gold-catalyzed peptide modifications can improve target specificity, modulate protein–protein interactions, and enable precise control over functional group incorporation. This review focuses on the latest advancements in gold-catalyzed site-selective functionalization of peptides, by providing a detailed overview of these developments, we aim to increase understanding in the field and encourage further exploration of gold-mediated peptide modifications.

Extraction of gold from electronic waste was commonly conducted using aqua regia. Here, we have shown a method to produce chloroauric acid in a salt solution by bipolar AC electrolysis. The developed bipolar AC electrolysis method provides an environment-friendly process to extract gold from electronic waste containing gold without using any strong acids such as aqua regia. 

Cancer is a significant global health issue that requires innovative methods for diagnosis and treatment. Gold nanoparticles (AuNPs) are becoming more popular due to their unique physical and chemical properties, having ability to interact with biological systems without causing harm, and their ease of modification. This paper examines the potential of AuNPs to transform cancer theranostic via the integration of diagnostics and treatment. We explore the use of AuNPs in cancer imaging, specifically examining their ability to enhance contrast in several imaging techniques, enabling the early and accurate detection of tumors. In addition, we discuss the use of AuNP-mediated photothermal therapy (PTT), where AuNPs convert light into heat to selectively destroy cancer cells. In addition, we are exploring the capacity of AuNPs to serve as carriers for drug delivery, enabling the specific delivery of chemotherapeutic agents to tumor sites while reducing the overall negative effects on the body. One of the key advantages of AuNPs emphasized in this review is their ability to integrate therapeutic and imaging characteristics. We analyze the current challenges and propose strategies to improve the delivery and design of AuNPs for more effective cancer theranostic. AuNPs show great potential for personalized and effective cancer treatment since they may connect diagnosis and therapy.