Gold Bulletin最新文献

Owing to their highly interesting applications in medicine, catalysis, and their luminescence properties, over the past decade, increasing efforts have been devoted to the synthesis of organo-gold(III) complexes. Therefore, the design of mild, practical, and modular protocols for their synthesis is a highly active field of research. In a recent paper in Angewandte Chemie, Hashmi and co-workers developed an efficient and solvent-free method for the mechanochemical synthesis of differently organo-gold(III) complexes; this method opens up a new perspective for the field.

The influence of the orientation of gold nanorods in different assemblies has been investigated using the finite difference time domain (FDTD) simulation method. To understand the relative orientation, we vary the size and angle in dimer geometries. Significant effects of plasmon coupling emerged in longitudinal resonances having end-to-end configurations of gold nanorods. The effect of orientational plasmon coupling in dimers gives rise to both bonding and anti-bonding plasmon modes. Effects of various geometries like primary monomer, dimer, trimer, and tetramer structures have been explored and compared with their higher nanorod ensembles. The asymmetric spectral response in a 4 × 4 gold nanorods array indicates a Fano-like resonance. The variation of gap distance in ordered arrays allowed modulation of the Fano resonance mode. The plasmon modes’ resonance wavelength and field enhancement have been tuned by varying the gap distance, angular orientation, size irregularity between the nanorods, and nanorod numbers in an array. The integrated nanostructures studied here are not only significant for fundamental research but also applications in plasmon-based devices.

Cancer is still one of the most common causes of death today despite advances in its detection and treatment. The present article reviews the application of marine-based gold nanoparticles in the diagnosis and treatment of cancer. The main data were collected from original research articles on the application of different marine-based gold nanoparticles in detecting and imaging cancer cells as well as in drug delivery systems and treatment of cancer. The results show the excellent anticancer potential of both gold nanoparticles and natural marine products. The most studied marine-based gold nanomaterial was chitosan-based ones, in which the role of chitosan is a stabilizer not an anticancer agent. Despite the excellent anticancer potential of different marine natural products, limited studies have been conducted using gold nanoparticles in their composition in cancer therapy. Moreover, most of these studies are related to their application as a drug delivery system not an anticancer drug. Although there are serious challenges in the application of nanoparticles in medicine, marine-based gold nanomaterials may promise an interesting novel strategy in the oncology field.

A simple template-free method was developed for the fabrication of fibers whose surfaces were covered by a three-dimensional interconnected network of Au nanostructures (3D-NW AuNSs) without additional stabilizer. The EDS and XPS measurements confirmed the metallic nature of the formed 3D gold nanowire networks on the fiber surface. The morphology of these 3D-NW AuNSs can be controlled by the experimental parameters, such as reaction time, roughness of the glass fiber surface, HAuCl₄, and sodium citrate concentration. The 3D gold nanowire networks showed excellent uniformity. Additionally, the nanofiber was used to accurately and reliably detect methyl red (MR), crystal violet (CV), and acridine orange (AO), which can be detected as low as 1, 10, and 5 μg/L, respectively. Since the proposed strategy is simple, cost-effective, and reproducible for the mass production of network-like gold film–covered nanofiber, it is expected to play an important role in the development of trace analytical devices.

The different coordination modes in carbon-gold(I) complexes are spotlighted with a focus on gold(I). The emergence of gold carbene complexes and their critical discussion in the community is presented, and an overview of their bonding fundamentals and synthetic procedures is given. Several intriguing and sometimes highly reactive gold-carbon coordination complexes that were recently synthesised and isolated are reviewed and a critical outlook into their potential applications is provided. This includes vinylidene and higher cumulenylidene complexes, free carbenes with gold substituents, carbodicarbene complexes, and non-Fischer/Schrock sesquicarbene complexes.

A series of gold nanoparticles were synthesized by stepwise growth method under the condition of citrate as a reducing agent and stabilizer. The optical properties with the maximum absorption wavelength (λ_max) and electrochemical properties of the oxidation potential (E_p) dependence on the particle size were analyzed. The method of calculating the particle size from the UV-visible spectrum and the electrochemical oxidation peak was deduced, following the theoretical prediction trend and consistent with previous observations. Furthermore, we investigated the application performance based on the electrochemical catalytic activity and the aggregation of the spherical gold nanoparticles using L-cysteine as a target. The results indicated that the optical and electrochemical properties of the gold nanoparticles to L-cysteine were closely related to the particle size of gold nanoparticles. With the increased size of the nanoparticles, the full width at half maximum in the UV-visible absorption spectrum increased and the electrochemical oxidation potential was positively shifted.