gold nanocluster

To address the need for facile, rapid detection of pathogens in water supplies, a fluorescent sensing array platform based on antibiotic-stabilized metal nanoclusters was developed for the multiplex detection of pathogens. Using five common antibiotics, eight different nanoclusters (NCs) were synthesized including ampicillin stabilized copper NCs, cefepime stabilized gold and copper NCs, kanamycin stabilized gold and copper NCs, lysozyme stabilized gold NCs, and vancomycin stabilized gold/silver and copper NCs...

Herein, a novel fluorescent/colorimetric/photothermal biosensor is proposed for aflatoxin B1 (AFB1) detection in food based on Prussian blue nanoparticles (PBNPs) (∼50 nm), gold nanoclusters (AuNCs), and an aptamer (Apt) within three hours. Briefly, a multifunctional compound, namely PBNPs-PEI@AuNCs, was synthesized from PBNPs as the loading carrier, polyethyleneimine (PEI) as the cross-linking agent, and AuNCs directly combined on the surface of PBNPs. The AFB1 Apt was then modified on the PBNPs-PEI@AuNCs to form a PBNPs-PEI@AuNCs-Apt probe, whereby when AFB1 is present, AFB1 is specifically captured by the probe...

Currently, fluorescent "turn-on" lateral flow assay (FONLFA) has shown enhanced "naked eye" detection sensitivity for small molecules, while it is urgent to adopt biocompatible fluorescent nanomaterials and needs new strategies to simplify the preparation process. In this study, a highly effective method was proposed to produce FONLFA strips for the detection of small molecules. The gold-silver nanoclusters (AuAgNCs) were immobilized onto the nitrocellulose membrane of the strips by the self-assembly of poly(sodium 4-styrenesulfonate), antigen, and AuAgNCs...

Au(III) is highly reactive. At odds with its reduced counterpart, Au(I), it is hardly present in structural databases. And yet, it is the starting reactant to form gold nanoclusters (AuNCs) and the constitutive component of a new class of drugs. Its reactivity is a world apart from that of the iso-electronic Pt(II) species. Rather than DNA, it targets proteins. Its interaction with amino acid residues is manifold. It can strongly interact with the residue backbones, amino acid side chains and protein ends, it can form appropriate complexes whose stabilization energy reaches up to more than 40 kcal mol-1 , it can affect the p K a of amino acid residues, and it can promote charge transfer from the residues to the amount that it is reduced...

The metal exchange reaction has emerged as an efficient method to synthesize ligand-protected alloy nanoclusters with precise compositions and structure. However, the understanding of the mechanism of these metal exchange processes is quite limited. Herein, the dynamic process of metal exchange of Au25 (SR)18 - and Ag25 (SR)18 - (R = CH3 ) nanoclusters with metal ions (Au+ , Ag+ , Cu2+ , Cu+ , Cd2+ , and Hg2+ ) is investigated using ab initio molecular dynamics simulations. Computational results unveiled a multifaceted nature of the metal exchange process, dictated by several variables, including thermodynamic stability, electrochemical activity, metal affinity to ligand, and the coordination mode of metal ions...

BACKGROUND: Inorganic pyrophosphatase (PPase) is key enzyme playing a key role in biochemical transformations such as biosynthesis of DNA and RNA, bone formation, metabolic pathways associated with lipid, carbohydrate and phosphorous. It has been reported that lung adenocarcinomas, colorectal cancer, and hyperthyroidism disorders can result from abnormal level of PPase. Therefore, it is of notable significance to develop simple and effective real time assay for PPase enzyme activity monitoring for screening of many metabolic pathways as well as for early disease diagnosis...

A dual-color ratiometric fluorescence sensor based on photonic crystals (PCs) was developed to detect tetracycline (TC) in food. PC was fabricated via self-assembly of carbon dots (CDs)-loaded SiO2 nanoparticles. Gold nanoclusters (AuNCs) and copper ions (Cu2+ ) were then adsorbed onto the PC for sensor fabrication. The fluorescence of AuNCs was amplified by the PC with an enhancement ratio of 7.6, providing higher sensitivity. The fluorescence of AuNCs was quenched by Cu2+ , whereas that of CDs remained unchanged as an internal reference...

Blue emissive Argyreia nervosa-capped gold nanoclusters (A. nervosa-AuNCs) were synthesized via a simple environment-friendly method. The developed probe exhibits rapid response towards the target analyte (hexaconazole fungicide). Several characterizations, including FT-IR, UV-visible, fluorescence, HR-TEM, XPS, and fluorescence lifetime, were studied to confirm the formation of A. nervosa-AuNCs. The A. nervosa-AuNCs displayed emission and excitation peaks at 470 and 390 nm, respectively. Furthermore, the quantum yield (QY) of A...

Designing luminophores bright in both isolate species and aggregate states is of great importance in many emerging cutting-edge applications. However, the conventional luminophores either emit in isolate species but quench in aggregate state or emit in aggregate state but darken in isolate species. Here we demonstrate that the precise regulation of noncovalent interactions can realize luminophores bright in both isolate species and aggregate states. It is firstly discovered that the intra-cluster interaction enhances the emission of atomically precise Au25(pMBA)18 (pMBA = 4-mercaptobenzoic acid), a nanoscale luminophore, while the inter-cluster interaction quenches the emission...

Natural enzymes intricately regulate substrate accessibility through specific amino acid sequences and folded structures at their active sites. Achieving such precise control over the microenvironment has proven to be challenging in nanocatalysis, especially in the realm of ligand-stabilized metal nanoparticles. Here, we use atomically precise metal nanoclusters (NCs) as model catalysts to demonstrate an effective ligand engineering strategy to control the local concentration of CO2 on the surface of gold (Au) NCs during electrocatalytic CO2 reduction reactions (CO2 RR)...

Lead pollution has remained a significant global concern for several decades due to its detrimental effects on the brain, heart, kidneys, lungs, and immune system across all age groups. Addressing the demand for detecting trace amounts of lead in food samples, we have developed a novel biosensor based on fluorescence resonance energy transfer (FRET) from fluorescein R6G to gold nanoclusters (AuNCs-CCY). By utilizing polypeptides as a template, we successfully synthesized AuNCs-CCY with an excitation spectrum that overlaps with the emission spectrum of R6G...

Single-molecule localization microscopy has proved promising to unravel the dynamics and molecular architecture of thin biological samples down to nanoscales. For applications in complex, thick biological tissues shifting single-particle emission wavelengths to the shortwave infrared (SWIR also called NIR II) region between 900 to 2100 nm, where biological tissues are more transparent is key. To date, mainly single-walled carbon nanotubes (SWCNTs) enable such applications, but they are inherently 1D objects...

Extracellular vesicles (EVs) are well-known membrane-limited particles secreted by both healthy and cancerous cells. They are considered as biomarkers for early cancer diagnosis and are involved in many pathologies and physiological pathways. They could serve as diagnostic tools in liquid biopsies, as therapeutics in regenerative medicine, or as drug delivery vehicles. Our aim is here to encapsulate luminescent nanoprobes in the aqueous compartment of human EVs extracted from reproductive fluids. The analysis and labeling of the EVs content with easily detectable luminescent nanoparticles could enable a powerful tool for early diagnosis of specific diseases and also for the design of new therapeutics...

Ultrasmall fluorescent nanomaterials have been widely studied as novel fluorescent probes; however, these nanomaterials are prone to structural damage or aggregation, and the sensitivity and accuracy of most single emission fluorescence probes were very low. Therefore, the controlled synthesis of stable dual-emission ratiometric fluorescence ultrasmall assembly probes still remains a challenge. Herein, star-like polymer unimolecular micelles were utilized as a scaffold template to encapsulate fluorescent ultrasmall carbon quantum dots (CQDs) and gold nanoclusters (AuNCs) via the polymer template directed self-assembly strategy to obtain multiple-responsive ratiometric fluorescent assemblies...

N -Heterocyclic carbenes (NHCs) have emerged as promising ligands for stabilizing metallic complexes, nanoclusters, nanoparticles (NPs) and surfaces. The carbon-metal bond between NHCs and metal atoms plays a crucial role in determining the resulting material's stability, reactivity, function, and electronic properties. Using Raman spectroscopy coupled with density functional theory calculations, we investigate the nature of carbon-metal bonding in NHC-silver and NHC-gold complexes as well as their corresponding NPs...

The development of efficient, accurate, and high-throughput technology for gut microbiota sensing holds great promise in the maintenance of health and the treatment of diseases. Herein, we developed a rapid fluorescent sensor array based on surface-engineered silver nanoparticles (AgNPs) and vancomycin-modified gold nanoclusters (AuNCs@Van) for gut microbiota sensing. By controlling the surface of AgNPs, the recognition ability of the sensor can be effectively improved. The sensor array was used to successfully discriminate six gut-derived bacteria, including probiotics, neutral, and pathogenic bacteria and even their mixtures...

Gold nanoclusters (Au NCs) with bright emission and unique chemical reactivity characters have been widely applied for optical sensing and imaging. With a combination of surface modifications, effective therapeutic treatments of tumors are realized. In this review, we summarize the recently adopted biosensing and therapy events based on Au NCs. Homogeneous and fluorometric biosensing systems toward various targets, including ions, small molecules, reactive oxygen species, biomacromolecules, cancer cells, and bacteria, in vitro and in vivo, are presented by turn-off, turn-on, and ratiometric tactics...

A difficult issue in chemistry and materials science is to create metal compounds with well-defined components. Metal nanoclusters, particularly those of coinage groups (Cu, Ag, and Au), have received considerable research interest in recent years owing to the availability of atomic-level precision via joint experimental and theoretical methods, thus revealing the mechanisms in diverse nano-catalysts and functional materials. The textile sector significantly contributes to wastewater containing pollutants such as dyes and chemical substances...

Innovative surface-protecting ligands are in constant demand due to their crucial role in shaping the configuration, property, and application of gold nanoclusters. Here, the unprecedented O -ethyl dithiocarbonate (DTX)-stabilized atomically precise gold nanoclusters, [Au25 (PPh3 )10 (DTX)5 Cl2 ]2+ ( Au 25 DTX -Cl ) and [Au25 (PPh3 )10 (DTX)5 Br2 ]2+ ( Au 25 DTX -Br ), were synthesized and structurally characterized. The introduction of bidentate DTX ligands not only endowed the gold nanocluster with unique staggered Au25 nanorod configurations but also generated the symmetry breaking from the D 5d geometry of the Au25 kernels to the chiral D 5 configuration of the Au25 molecules...

On-demand controlled drug release holds great promise for cancer therapy. Light-degradable nanocarriers have gained increasing attention for designing controllable drug delivery systems owing to their spatiotemporally controllable properties. Herein, a highly luminescent and light-degradable nanocarrier is constructed by intercalating glutathione-capped gold nanoclusters (AuNCs) into zeolitic imidazolate framework-8 (ZIF-8) via competitive coordination assembly, named AuNC@ZIF-8, for light-triggered drug release...