We report the assembly of gold nanoclusters by the nonthiolate ligand diglyme into discrete and dynamic assemblies. To understand this surprising phenomenon, the assembly of Au20(SC2H4Ph)15-diglyme into Au20(SC2H4Ph)15-diglyme-Au20(SC2H4Ph)15 is explored in detail. The assembly is examined by high-angle annular dark field scanning transmission electron microscopy, size exclusion chromatography, mass spectrometry, IR spectroscopy, and calorimetry. We establish a dissociation constant for dimer to monomer conversion of 20.4 μM. Theoretical models validated by transient absorption spectroscopy predict a low-spin monomer and a high-spin dimer, with assembly enabled through weak diglyme oxygen-gold interactions. Close spatial coupling allows electron delocalization between the nanoparticle cores. The resulting assemblies thus possess optical and electronic properties that emerge as a result of assembly.
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http://dx.doi.org/10.1021/acsnano.5b02850 | DOI Listing |
Sci Rep
January 2025
Department of Chemistry, Federal University of Paraná, Curitiba, 81531-980, Brazil.
Gold-based (Au) nanostructures are efficient catalysts for CO oxidation, hydrogen evolution (HER), and oxygen evolution (OER) reactions, but stabilizing them on graphene (Gr) is challenging due to weak affinity from delocalized [Formula: see text] carbon orbitals. This study investigates forming metal alloys to enhance stability and catalytic performance of Au-based nanocatalysts. Using ab initio density functional theory, we characterize [Formula: see text] sub-nanoclusters (M = Ni, Pd, Pt, Cu, and Ag) with atomicities [Formula: see text], both in gas-phase and supported on Gr.
View Article and Find Full Text PDFChem Asian J
January 2025
Towson University, 8000 York Road, SC 3301B, 21252, Towson, UNITED STATES OF AMERICA.
Au nanoclusters often demonstrate useful optical properties such as visible/near-infrared photoluminescence in addition to remarkable thermodynamic stability owing to their superatomic behavior. The smallest of the 8e- superatomic Au nanoclusters, Au11, has limited applications due to its lack of luminescence and relatively low stability. In this work, we investigate the introduction of a single Pt dopant to the center of a halide- and triphenylphosphine-ligated Au11 nanocluster, obtaining a cluster with a proposed molecular formula PtAu10(PPh3)7Br3.
View Article and Find Full Text PDFAnal Chem
January 2025
Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Box 332, Shenyang 110819, China.
The advancement of lanthanide fingerprint sensors characterized by targeted emission responses and low self-fluorescence interference for the detection of biothiols is of considerable importance for the early diagnosis and treatment of cancer. Herein, the lanthanide "personality function tailoring" HOF composite sensor array is designed for the specific discrimination of biothiols (GSH, Cys, and Hcy) based on the activation of various luminescent molecules, such as r-AuNCs/luminol via HOF surface proximity. Lumi-HOF@Ce serves as a versatile platform for catalyzing the oxidation of -phenylenediamine (OPD) to generate yellow fluorescent oligomers, accompanied by the fluorescence attenuation of luminol.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Tianjian Laboratory of Advanced Biomedical Sciences, Institute of Advanced Biomedical Sciences, Henan International Joint Laboratory of Tumor Theranostic Cluster Materials, Henan Key Laboratory of Crystalline Molecular Functional Materials, College of Chemistry, Zhengzhou University, 450001, Zhengzhou, China. Electronic address:
Background: Integrating natural enzymes and nanomaterials exhibiting tailored enzyme-like activities is an effective strategy for the application of cascade reactions. It is essential to develop a highly efficient and robust glucose oxidase-catalase (GOx-CAT) cascade system featuring controllable enzyme activity, a reliable supply of oxygen, and improved stability for glucose depletion in cancer starvation therapy. However, the ambiguous relationship between structure and performance, and the difficulty in controlling enzyme-mimic activity, significantly hinder their broader application.
View Article and Find Full Text PDFChem Asian J
January 2025
Universidad Austral de Chile, Instituto de Ciencias Químicas, CHILE.
Plasmonic materials can be utilized as effective platforms to enhance luminescent signals of luminescent metal nanoclusters (LMNCs). Both surface enhanced fluorescence (SEF) and shell-isolated nanoparticle-enhanced fluorescence (SHINEF) strategies take advantage of the localized and increased external electric field created around the plasmonic metal surface when excited at or near their characteristic plasmonic resonance. In this context, we present an experimental and computational study of different plasmonic composites, (Ag) Ag@SiO2 and (Au) Au@SiO2 nanoparticles, which were used to enhance the luminescent signal of Au nanoclusters coated with glutathione (GSH) molecule (Au25GSH NCs).
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