Gold-ATP

Preparation and high-resolution microscopy of gold cluster labeled nucleic acid conjugates and nanodevices

Nanogold and undecagold are covalently linked gold cluster labels which enable the identification and localization of biological components with molecular precision and resolution. They can be prepared with different reactivities, which means they can be conjugated to a wide variety of molecules, including nucleic acids, at specific, unique sites. The location of these sites can be synthetically programmed in order to preserve the binding affinity of the conjugate and impart novel characteristics and useful functionality. Methods for the conjugation of undecagold and Nanogold to DNA and RNA are discussed, and applications of labeled conjugates to the high-resolution microscopic identification of binding sites and characterization of biological macromolecular assemblies are described. In addition to providing insights into their molecular structure and function, high-resolution microscopic methods also show how Nanogold and undecagold conjugates can be synthetically assembled, or self-assemble, into supramolecular materials to which the gold cluster labels impart useful functionality.

Facile, large-scale synthesis of dodecanethiol-stabilized Au38 clusters

It has long been a major challenge to achieve synthetic control over size and monodispersity of gold thiolate nanoclusters. Among the reported Aun thiolate clusters, Au38 has been shown to be particularly stable but was only obtained as a minor product in previous syntheses. In this work, we report a bulk solution synthetic method that permits large-scale, facile synthesis of truly monodisperse Au38 nanoclusters. This new method explores a two-phase ligand exchange process utilizing glutathione-capped Aun clusters as the starting material. The ligand exchange process with neat dodecanethiols causes gold core etching and secondary growth of clusters, and eventually leads to monodisperse Au38 clusters in high purity, which eliminates nontrivial postsynthetic separation steps. This method can be readily scaled up to synthesize Au38(SC12H25)24 in large quantities and thus makes the approach and Au38 nanoclusters of broad utility.

Nucleotide passivated cadmium sulfide quantum dots

Semiconductor quantum dots are finding numerous applications in biological systems; in this paper, we report the simple in situ preparation of nucleotide capped cadmium sulfide (CdS) nanoparticles and investigate the interaction of the capping agent with the nanoparticle surface.

New frontiers in gold labeling

Recent advances in gold technology have led to probes with improved properties and performance for cell biologists: higher labeling density, better sensitivity, and greater penetration into tissues. Gold clusters, such as the 1.4-nm Nanogold, are gold compounds that can be covalently linked to Fab' antibody fragments, making small and stable probes. Silver enhancement then makes these small gold particles easily visible by EM, LM, and directly by eye. Another advance is the combination of fluorescent and gold probes for correlative microscopy. Chemical crosslinking of gold particles to many biologically active molecules has made possible many novel probes, such as gold-lipids, gold-Ni-NTA, and gold-ATP.