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Rapid Size-Focusing of Gold Nanoclusters with an Oxidant
摘要： Rapid size-focusing of gold nanoclusters can be achieved by the addition of K3[Fe(CN)]6. The conditions for this have been optimized, and the possible role that it plays proposed.
关键词： Gold,Oxidant,Size-focusing,Nanocluster
更新于2025-09-23 15:21:01
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Tailoring the Core–Satellite Nanoassembly Architectures by Tuning Internanoparticle Electrostatic Interactions
摘要： The use of plasmonic nanoplatforms has received increasing interest in a wide variety of fields ranging from theranostics to environmental sensing to plant biology. In particular, the development of plasmonic nanoparticles into ordered nanoclusters has been of special interest due to the new chemical functionalities and optical responses that they can introduce. However, achieving predetermined nanocluster architectures from bottom-up approaches in the colloidal solution state still remains a great challenge. Herein, we report a one-pot assembly approach that provides flexibility in precise control of core?satellite nanocluster architectures in the colloidal solution state. We found that the pH of the assembly medium plays a vital role in the hierarchy of the nanoclusters. The architecture along with the size of the satellite gold nanoparticles determines the optical responses of nanoclusters. Using electron microscopy and optical spectroscopy, we introduce a set of design rules for the synthesis of distinct architectures of silica-core gold satellites nanoclusters in the colloidal solution state. Our findings provide insight into advancing the colloidal solution state nanoclusters formation with predictable architectures and optical properties.
关键词： optical responses,colloidal solution state,plasmonic nanoplatforms,core?satellite nanocluster architectures,pH-dependent assembly
更新于2025-09-23 15:21:01
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Single Au Atom Doping of Silver Nanoclusters
摘要： Ag29 nanoclusters capped with lipoic acid (LA) can be doped with Au. The doped clusters show enhanced stability and increased luminescence efficiency. We attribute the higher quantum yield to an increase in the rate of radiative decay. With mass spectrometry, the Au-doped clusters were found to consist predominantly of Au1Ag28(LA)12 3 – . The clusters were characterized using X-ray absorption spectroscopy at the Au L3-edge. Both the extended absorption fine structure (EXAFS) and the near edge structure (XANES) in combination with electronic structure calculations confirm that the Au dopant is preferentially located in the center of the cluster. A useful XANES spectrum can be recorded for lower concentrations, or in shorter time, than the more commonly used EXAFS. This makes XANES a valuable tool for structural characterization.
关键词： x-ray spectroscopy,structure elucidation,doping,Au1Ag28,Ag29,luminescence,bimetallic nanocluster
更新于2025-09-23 15:21:01
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Tuning Hydrogenated Si, Ge, and SiGe Nanocluster Properties Using Theoretical Calculations and a Machine Learning Approach
摘要： There are limited studies available that predict the properties of hydrogenated silicon-germanium (SiGe) clusters. For this purpose, we conducted a computational study of 46 hydrogenated SiGe clusters (SixGeyHz, 1<X+Y≤6) to predict the structural, thermochemical, and electronic properties. The optimized geometries of the SixGeyHz clusters were investigated using quantum chemical calculations and statistical thermodynamics. The clusters contained 6 to 9 fused Si-Si, Ge-Ge, or Si-Ge bonds, i.e., bonds participating in more than one 3- to 4-membered rings, and di?erent degrees of hydrogenation, i.e., the ratio of hydrogen to Si/Ge atoms varied depending on cluster size and degree of multifunctionality. Our studies have established trends in standard enthalpy of formation, standard entropy, and constant pressure heat capacity as a function of cluster composition and structure. A novel bond additivity correction model for SiGe chemistry was regressed from experimental data on 7 acyclic Si/Ge/SiGe species to improve the accuracy of the standard enthalpy of formation predictions. Electronic properties were investigated by analysis of the HOMO–LUMO energy gap to study the effect of elemental composition on the electronic stability of SixGeyHz clusters. These properties will be discussed in the context of tailored nanomaterials design and generalized using a machine learning approach.
关键词： Theoretical Calculations,SiGe Nanocluster,Ge,Machine Learning,Hydrogenated Si,Quantum Chemistry,Spectroscopy,Molecular Structure
更新于2025-09-23 15:21:01
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Controlled deposition of size-selected metal nanoclusters on prepatterned substrate
摘要： An endeavor of organizing Cu nano-particles of controlled size in ordered arrays at room temperature is reported. This involves the guided deposition of size-selected nanoparticles otherwise known as nanoclusters via periodic modulation of the substrate surface. Ultra-high vacuum compatible magnetron-based gas-aggregation type source combined with a quadrupole mass filter has been employed to produce the size-selected nanoclusters whereas the surface modulations (ripples) in the nanoscale are induced by low energy oblique angle ion beam irradiation. Morphological aspects of deposited nanoclusters and the substrates were characterized by high-resolution scanning electron microscopy (HRSEM) and atomic force microscopy (AFM). The chemical composition of the deposited nanoclusters was characterized by x-ray photoelectron spectroscopy. The alignment of size-selected metal nanoclusters along the substrate-patterns is observed. Depending upon deposition conditions quality of the organization varies. The optimum angle of deposition for the improved alignment depends on the pattern parameters of the substrate.
关键词： Ion sputtering,Room-temperature organization,Metal nanocluster,Patterned substrate,Supported clusters,Scanning Electron Microscopy
更新于2025-09-23 15:19:57
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Polysaccharide enabled biogenic fabrication of pH??sensing fluorescent gold nanoclusters as a biocompatible tumor imaging probe
摘要： A biocompatible natural polysaccharide (PSP001) isolated from the fruit rind of Punica granatum was conjugated with L-cysteine (Y) to be used as a skeleton for the fabrication of fluorescent gold nanoclusters (AuNCs) represented as PSP-Y-AuNCs. With an average size of ~ 6 nm, PSP-Y-AuNCs demonstrated high quantum yield (31%), with a pH-sensitive fluorescence emission behavior. An emission maximum of 520 nm was obtained at acidic pH, which was blue shifted with increasing pH. This feature provides the possibilities for accurate ratiometric pH imaging. The PSP-Y-AuNCs not only demonstrated excellent biocompatibility with cancer cells and isolated peripheral lymphocytes and red blood cells but also demonstrated to be an active molecular imaging probe with appealing cellular uptake efficiency. The investigations with BALB/c mice further confirmed the non-toxic nature and in vivo imaging potential of the AuNCs. Estimation of the bio-distribution on solid tumor bearing syngeneic murine models revealed a tumor-targeted enhanced fluorescence emission pattern which is attributed to the pH responsive fluorescence behavior and the acidic microenvironment of the tumor. These findings were further confirmed with an impressive tumor accumulation pattern displayed in a xenograft of human cancer bearing nude mice. On account of their impressive biocompatibility and photophysical features, PSP-Y-AuNCs can exploited for the real-time fluorescence imaging of cancer tissues.
关键词： Polysaccharide,Tumor,pH ratiometry,Biocompatibility,In vivo imaging,Nanocluster,Fluorescence,Punica granatum,Gold nanoparticle
更新于2025-09-23 15:19:57
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Surface Enhanced Raman Spectra and Theoretical Study of an Organophosphate Malathion
摘要： Surface Enhanced Raman Scattering (SERS) is an established technique for the rapid and sensitive analysis of chemicals, pesticides and pharmaceuticals. The aim of this work is to develop sensitive and cost effective SERS substrates for pesticide detection using modified mirror reaction and physical deposition method. The prepared substrates were examined using Field Emission Scanning Electron Microscope (FESEM). The prepared slides were then used to detect an organophosphate pesticide, Malathion. The available simple geometry of Malathion was optimized using 6-311++G(d,p) basis set of Gaussian 09 software. The experimental Raman spectra, Surface Enhanced Raman spectra and theoretically computed wavenumbers are compared and the results are presented briefly.
关键词： modified mirror reaction,FESEM,nanocluster deposition,Malathion
更新于2025-09-23 15:19:57
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Label-free Fluorescence “Turn-on” Detection of SO <sub/>3</sub><sup>2-</sup> by Gold Nanoclusters: Integration in a Hydrogel Platform and Intracellular Detection
摘要： A facile approach for the fluorescence based detection of sulfite (SO3 2-) using gold nanoclusters (Au NCs) has been reported. The detection assay relies on the effective quenching of the fluorescence of Au NCs in the presence of Cu2+, which could eventually be recovered upon the addition of SO3 2-. The proposed Cu2+ assisted fluorescence 'turn-on' detection method for SO3 2- was highly sensitive and demonstrated a linear response towards SO3 2- within the desired concentration range. Importantly, the sensing system possessed high selectivity for SO3 2- compared to other competitive anionic analytes, allowing for an analytically robust and reliable detection. Further, fluorescent Au NC-hydrogels were developed, which advise a path forward for the solid sensing platforms for detection of SO3 2- in aqueous solutions, making it a meaningful approach for instrument-free and visual monitoring. Owing to excellent analytical characteristics, Au NCs were successfully employed for intracellular SO3 2- detection. Therefore, the present study encompasses the manifold detection aspects of Au NCs based sensors.
关键词： Hydrogel,Intracellular,Gold nanocluster,Sulfite,Fluorescence turn-on
更新于2025-09-19 17:15:36
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Amphiphilicity Regulation of Ag(I) Nanoclusters: Self-Assembly and its Application as Luminescent Probe
摘要： Research on the self-assembly of various amphiphilic molecules is relatively hot and of great significance. However, new kind of metal nanoclusters (NCs) based amphiphilic molecule has rarely been explored. Herein, hydrophobic cations 1-hexadecyl-3-methylimidazolium (C16mim+) were chosen to modify hydrophilic (NH4)6[Ag6(mna)6] (Ag6-NCs, H2mna = 2-mercaptonicotinic acid) and Ag6@C16mim-NCs were obtained. Ag6@C16mim-NCs performed a thermotropic liquid crystal and thermofluorescence property. Moreover, the Ag6@C16mim-NCs exhibits benign amphiphilicity which could self-assembly into ordered nanosheets and nanorods aggregates in water/dimethyl sulfoxide (DMSO) binary solvents while single Ag6-NCs does not. Meanwhile, the Ag6@C16mim-NCs also performs aggregation-induced emission (AIE) property owing to the restriction of intramolecular vibration of the capping ligands. Furthermore, it can be found that the luminescent aggregates could detect arginine selectively with the detection limit (DL) at 28 uM. This study introduced a new kind of metal NCs-based amphiphilic molecule in a supramolecular self-assembly field and make it a candidates as optical materials in applied research.
关键词： Silver (I) nanocluster,aggregation-induced emission,self-assembly,amphiphilicity,sensor
更新于2025-09-19 17:15:36
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Hexavalent Octahedral Template: A Neutral High-Nucleus Silver Alkynyl Nanocluster Emitting Infrared Light
摘要： The first silver nanocluster with an octahedral template of TeO6 6? was synthesized as a neutral 36-nucleus nanocluster, and its structure was demonstrated using single-crystal X-ray diffraction, Fourier transform infrared spectroscopy, electrospray ionization mass spectrometry, and X-ray photoelectron spectroscopy. The peripheral ligands of the cagelike skeleton of the nanocluster are CF3COO? and tBuCC?. During the synthesis, the TeO6 6? template arranged the nanocluster, and a 36-nucleus nanocluster was formed. The effect of the template nature was displayed on the structural features of the nanocluster in comparison with an 8-nucleus cluster, with the same synthesis conditions. The photoluminescence and UV?vis absorption analyses of the nanocluster were also investigated. The nanocluster displayed near-infrared luminescence emission at 690 nm.
关键词： TeO6 6?,photoluminescence,silver nanocluster,octahedral template,infrared light
更新于2025-09-19 17:13:59