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gold nanocluster

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https://www.readbyqxmd.com/read/28345880/detecting-proteins-glycosylation-by-a-homogeneous-reaction-system-with-zwitterionic-gold-nanoclusters
#1
Jinan Li, Jing Liu, Zheyi Liu, Yuan Tan, Xiaoyan Liu, Fangjun Wang
Homogeneous gold nanoclusters (Au NCs) have been widely utilized in drug delivery, chemical sensing, bioassays and bio-labeling due to their unique physical and chemical properties. However, little attention has been paid to their application in detecting protein post-translational modifications. Herein, we describe development of a homogeneous reaction system with water-soluble zwitterionic Au NCs to capture glycopeptides from complex biological samples. The unique characteristics of Au NCs, such as their molecular-like properties, the excellent homogeneity in aqueous solution, the organic solvent respon-sive precipitation, and the easy preparation in only 4...
March 27, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28337982/the-fourth-crystallographic-closest-packing-unveiled-in-the-gold-nanocluster-crystal
#2
Zibao Gan, Jishi Chen, Juan Wang, Chengming Wang, Man-Bo Li, Chuanhao Yao, Shengli Zhuang, An Xu, Lingling Li, Zhikun Wu
Metal nanoclusters have recently attracted extensive interest not only for fundamental scientific research, but also for practical applications. For fundamental scientific research, it is of major importance to explore the internal structure and crystallographic arrangement. Herein, we synthesize a gold nanocluster whose composition is determined to be Au60S6(SCH2Ph)36 by using electrospray ionization mass spectrometry and single crystal X-ray crystallography (SCXC). SCXC also reveals that Au60S6(SCH2Ph)36 consists of a fcc-like Au20 kernel protected by a pair of giant Au20S3(SCH2Ph)18 staple motifs, which contain 6 tetrahedral-coordinate μ4-S atoms not previously reported in the Au-S interface...
March 24, 2017: Nature Communications
https://www.readbyqxmd.com/read/28335193/facile-synthesis-of-gd-functionalized-gold-nanoclusters-as-potential-mri-ct-contrast-agents
#3
Wenjun Le, Shaobin Cui, Xin Chen, Huanhuan Zhu, Bingdi Chen, Zheng Cui
Multi-modal imaging plays a key role in the earlier detection of disease. In this work, a facile bioinspired method was developed to synthesize Gd-functionalized gold nanoclusters (Gd-Au NCs). The Gd-Au NCs exhibit a uniform size, with an average size of 5.6 nm in dynamic light scattering (DLS), which is a bit bigger than gold clusters (3.74 nm, DLS), while the fluorescent properties of Gd-Au NCs are almost the same as that of Au NCs. Moreover, the Gd-Au NCs exhibit a high longitudinal relaxivity value (r1) of 22...
April 9, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28328538/hyperbranched-polyamine-assisted-synthesis-of-dual-luminescent-gold-composite-with-ph-responsive-character
#4
Zhiqin Yuan, Yi Du, Yan He
We present a facile one-pot, two-step strategy to prepare water-soluble dual-luminescent gold nanodots (AuNDs) and few-atom gold nanocluster composites simultaneously by using high molecular weight and hyperbranched polyethyleneimine (hPEI) as the protection ligand and stabilization agent. It was found that in the presence of hPEI, Au(III) ion can be reduced to a metastable Au(I) charge state in aqueous solution. Subsequently, adding 11-mercaptoundonioic acid induces parallel pathways of restricted Au(I) assembly, leading to the formation of both red-emitting hPEI stabilized AuNDs and blue-emitting hPEI-protected Au8 nanoclusters...
March 22, 2017: Methods and Applications in Fluorescence
https://www.readbyqxmd.com/read/28322024/au-nanoclusters-and-photosensitizer-dual-loaded-spatiotemporal-controllable-liposomal-nanocomposites-enhance-tumor-photodynamic-therapy-effect-by-inhibiting-thioredoxin-reductase
#5
Fuping Gao, Weiping Zheng, Liang Gao, Pengju Cai, Ru Liu, Yaling Wang, Qing Yuan, Yuliang Zhao, Xueyun Gao
Photodynamic therapy (PDT) is a minimally invasive therapeutic procedure of tumors with high selectivity and low side effect. However, it is usually not efficient in long-lasting tumor control. One of the main reasons is tumor cells develop some protective mechanisms that help them to deal with oxidative stress in the environment. The thioredoxin system in cancer is an important antioxidant defense system. Au nanoclusters could effectively inhibit thioredoxin reductase (TrxR) in tumor cell cytoplasm. Herein, Au nanoclusters and photosensitizer Chlorine 6 (Ce6) are co-loaded in spatiotemporal controllable liposomal nanocomposites...
March 21, 2017: Advanced Healthcare Materials
https://www.readbyqxmd.com/read/28300064/observation-of-gold-sub-nanocluster-nucleation-within-a-crystalline-protein-cage
#6
Basudev Maity, Satoshi Abe, Takafumi Ueno
Protein scaffolds provide unique metal coordination environments that promote biomineralization processes. It is expected that protein scaffolds can be developed to prepare inorganic nanomaterials with important biomedical and material applications. Despite many promising applications, it remains challenging to elucidate the detailed mechanisms of formation of metal nanoparticles in protein environments. In the present work, we describe a crystalline protein cage constructed by crosslinking treatment of a single crystal of apo-ferritin for structural characterization of the formation of sub-nanocluster with reduction reaction...
March 16, 2017: Nature Communications
https://www.readbyqxmd.com/read/28295679/guiding-brain-tumor-surgery-via-blood-brain-barrier-permeable-gold-nanoprobes-with-acid-triggered-mri-serrs-signals
#7
Xihui Gao, Qi Yue, Zining Liu, Mengjing Ke, Xingyu Zhou, Sihan Li, Jianping Zhang, Ren Zhang, Liang Chen, Ying Mao, Cong Li
Surgical resection is a mainstay in the treatment of malignant brain tumors. Surgeons, however, face great challenges in distinguishing tumor margins due to their infiltrated nature. Here, a pair of gold nanoprobes that enter a brain tumor by crossing the blood-brain barrier is developed. The acidic tumor environment triggers their assembly with the concomitant activation of both magnetic resonance (MR) and surface-enhanced resonance Raman spectroscopy (SERRS) signals. While the bulky aggregates continuously trap into the tumor interstitium, the intact nanoprobes in normal brain tissue can be transported back into the blood stream in a timely manner...
March 15, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28287715/dual-recognition-f%C3%A3-rster-resonance-energy-transfer-based-platform-for-one-step-sensitive-detection-of-pathogenic-bacteria-using-fluorescent-vancomycin-gold-nanoclusters-and-aptamer-gold-nanoparticles
#8
Mengqun Yu, Hong Wang, Fei Fu, Linyao Li, Jing Li, Gan Li, Yang Song, Mark T Swihart, Erqun Song
The effective monitoring, identification, and quantification of pathogenic bacteria is essential for addressing serious public health issues. In this study, we present a universal and facile one-step strategy for sensitive and selective detection of pathogenic bacteria using a dual-molecular affinity-based Förster (fluorescence) resonance energy transfer (FRET) platform based on the recognition of bacterial cell walls by antibiotic and aptamer molecules, respectively. As a proof of concept, Vancomycin (Van) and a nucleic acid aptamer were employed in a model dual-recognition scheme for detecting Staphylococcus aureus (Staph...
March 27, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28281716/encapsulation-of-aggregated-gold-nanoclusters-in-a-metal-organic-framework-for-real-time-monitoring-of-drug-release
#9
Fangfang Cao, Enguo Ju, Chaoqun Liu, Wei Li, Yan Zhang, Kai Dong, Zhen Liu, Jinsong Ren, Xiaogang Qu
Gold nanoclusters (AuNCs), which have stable luminescence and negligible biotoxicity, are a promising candidate in biological fields. However, their low photoluminescence (PL) efficiency is unsatisfactory. Herein, aggregated gold nanoclusters (aAuNCs) were confined in a metal-organic framework (MOF) to maintain their aggregation, restrict the rotation of their ligands, and further improve their quantum yield (QY) to 7.74%. The aAuNCs-MOF exhibited high luminescence and good biocompatibility. More importantly, in addition to its pH-dependent luminescence and external porosity, the complex was applied for the first time in real-time monitoring of drug release...
March 10, 2017: Nanoscale
https://www.readbyqxmd.com/read/28281526/a-molecule-like-ptau24-sc6h13-18-nanocluster-as-an-electrocatalyst-for-hydrogen-production
#10
Kyuju Kwak, Woojun Choi, Qing Tang, Minseok Kim, Yongjin Lee, De-En Jiang, Dongil Lee
The theoretically predicted volcano plot for hydrogen production shows the best catalyst as the one that ensures that the hydrogen binding step is thermodynamically neutral. However, the experimental realization of this concept has suffered from the inherent surface heterogeneity of solid catalysts. It is even more challenging for molecular catalysts because of their complex chemical environment. Here, we report that the thermoneutral catalyst can be prepared by simple doping of a platinum atom into a molecule-like gold nanocluster...
March 10, 2017: Nature Communications
https://www.readbyqxmd.com/read/28277669/control-of-primary-particle-spacing-in-gold-nanoparticle-clusters-for-both-high-nir-extinction-and-full-reversibility
#11
Ehsan Moaseri, Robert J Stover, Behzad Changalvaie, Alexis J Cepeda, Thomas M Truskett, Konstantin Sokolov, Keith P Johnston
Reversible NIR-active nanoparticle clusters with controlled size from 20 to 100 nm were assembled from 5nm gold nanoparticles (Au NP), with either citrate (CIT) or various binary ligands on the surface, by tuning the electrostatic repulsion and the hydrogen bonding via pH. The nanoclusters were bound together by vdW forces between the cores and the hydrogen bonds between the surface ligands and dissociated to primary nanoparticles over a period of 20 days at pH 5 and at pH 7. When high levels of citrate ligands were used on the primary particle surfaces, the large particle spacings in the nanoclusters led to only modest NIR extinction...
March 9, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28276561/the-size-effect-of-gold-nanoparticles-and-nanoclusters-in-the-inhibition-of-amyloid-%C3%AE-fibrillation
#12
Guanbin Gao, Mingxi Zhang, Dejun Gong, Rui Chen, Xuejiao Hu, Taolei Sun
A significant pathological signature of Alzheimer's disease (AD) is the deposition of amyloid-β (Aβ) plaques in the brain and the synaptic dysfunction and neurodegeneration associated with it. Compounds or drugs that inhibit Aβ fibrillation are thus desirable to develop novel therapeutic strategies against AD. Conventional strategies usually require an elaborate design of their molecular structures. Here we report the size-effect of gold nanoparticles (AuNPs) and nanoclusters (AuNCs) in the inhibition of protein amyloidosis...
March 9, 2017: Nanoscale
https://www.readbyqxmd.com/read/28276344/a-new-fluorescence-turn-on-nanobiosensor-for-the-detection-of-micro-rna-21-based-on-a-dna-gold-nanocluster
#13
Morteza Hosseini, Elnaz Ahmadi, Yasaman-Sadat Borghei, Mohammad Reza Ganjali
In this study, DNA/gold nanoclusters (AuNCs) were used to develop an AuNC-based turn-on fluorescence probe for the analysis of mi-RNA-21, which is a potential screening biomarker for cancer detection. AuNCs on a DNA scaffold were prepared through a one-pot wet-chemical route and evaluated by transmission electron microscopy and dynamic light scattering. Experiments revealed that the fluorescence intensity of the DNA-AuNCs showed a gradual increase with the addition of the target species in a concentration range from 1pM to 10 nM...
March 8, 2017: Methods and Applications in Fluorescence
https://www.readbyqxmd.com/read/28248643/one-step-synthesis-of-boronic-acid-functionalized-gold-nanoclusters-for-photoluminescence-sensing-of-dopamine
#14
Huide Chen, Chunxiu Liu, Yunsheng Xia
This study is the first to report one-step synthesis of boronic acid functionalized gold nanoclusters (AuNCs) using mixed ligands of 4-mercaptophenylboronic acid (MPBA) and glutathione. Furthermore, the emission color of the products can be fancily tuned from green to near-infrared by simply changing the proportion of the two stabilizers. In basic media, dopamine (DA) molecules themselves polymerize each other and form polydopamine with large amounts of cis-diol groups, which then react with boronic acid groups on the AuNC's surface based on the formation of boronate esters...
March 1, 2017: Methods and Applications in Fluorescence
https://www.readbyqxmd.com/read/28223074/recent-advances-in-biomedical-applications-of-fluorescent-gold-nanoclusters
#15
REVIEW
Youkun Zheng, Lanmei Lai, Weiwei Liu, Hui Jiang, Xuemei Wang
Fluorescent gold nanoclusters (AuNCs) are emerging as novel fluorescent materials and have attracted more and more attention in the field of biolabeling, biosensing, bioimaging and targeted cancer treatment because of their unusual physicochemical properties, such as long fluorescence lifetime, ultrasmall size, large Stokes shift, strong photoluminescence, as well as excellent biocompatibility and photostability. Recently, significant efforts have been committed to the preparation, functionalization and biomedical application studies of fluorescent AuNCs...
February 16, 2017: Advances in Colloid and Interface Science
https://www.readbyqxmd.com/read/28217791/alkynyl-protected-gold-and-gold-silver-nanoclusters
#16
Zhen Lei, Xian-Kai Wan, Shang-Fu Yuan, Jia-Qi Wang, Quan-Ming Wang
Ligand-protected metal nanoclusters as unique nanomaterials have attracted great attention. The protecting ligands that directly bind on the cluster surfaces are crucial in dictating the structures and properties of the clusters. In contrast to the extensively studied thiolates, alkynyl ligands have been found recently to be important ligands for passivating gold/silver cluster surfaces. In this Frontier article, recent advances in alkynyl-protected metal nanoclusters are overviewed, and the structures, luminescence and catalytic activities are also discussed...
March 14, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28213327/visualizing-bpa-by-molecularly-imprinted-ratiometric-fluorescence-sensor-based-on-dual-emission-nanoparticles
#17
Hongzhi Lu, Shoufang Xu
Construction of ratiometric fluorescent probe often involved in tedious multistep preparation or complicated coupling or chemical modification process. The emergence of dual emission fluorescent nanoparticles would simplify the construction process and avoids the tedious chemical coupling. Herein, we reported a facile strategy to prepare ratiometric fluorescence molecularly imprinted sensor based on dual emission nanoparticles (d-NPs) which comprised of carbon dots and gold nanoclusters for detection of Bisphenol A (BPA)...
June 15, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28213326/amino-acid-mediated-turn-off-turn-on-nanozyme-activity-of-gold-nanoclusters-for-sensitive-and-selective-detection-of-copper-ions-and-histidine
#18
Yan Liu, Ding Ding, Yuanlin Zhen, Rong Guo
Herein, we presented a facile strategy for highly sensitive and selective detection of both Cu(2+) and histidine (His) by combining the peroxidase-like nanozyme activity of gold nanoclusters with amino acid's ambidentate nature. The peroxidase-like catalytic ability of histidine-Au nanoclusters (His-AuNCs) can be inhibited by the addition of Cu(2+). The sensitivity of this probe to Cu(2+) is significant with a linear range of 1-100nM, and a low detection limit of 0.1nM. More interestingly, His-AuNC/Cu(2+) undergoes recovery of the activity upon exposure to free His, because His/Cu(2+) complex is more stable due to the participation of the imidazole ring of His...
June 15, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28208642/photoluminescent-gold-nanoclusters-in-cancer-cells-cellular-uptake-toxicity-and-generation-of-reactive-oxygen-species
#19
Marija Matulionyte, Dominyka Dapkute, Laima Budenaite, Greta Jarockyte, Ricardas Rotomskis
In recent years, photoluminescent gold nanoclusters have attracted considerable interest in both fundamental biomedical research and practical applications. Due to their ultrasmall size, unique molecule-like optical properties, and facile synthesis gold nanoclusters have been considered very promising photoluminescent agents for biosensing, bioimaging, and targeted therapy. Yet, interaction of such ultra-small nanoclusters with cells and other biological objects remains poorly understood. Therefore, the assessment of the biocompatibility and potential toxicity of gold nanoclusters is of major importance before their clinical application...
February 10, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28177224/protein-stabilized-gadolinium-oxide-gold-nanoclusters-hybrid-for-multimodal-imaging-and-drug-delivery
#20
Lu Han, Jun-Mei Xia, Xin Hai, Yang Shu, Xu-Wei Chen, Jian-Hua Wang
A protein-stabilized multifunctional theranostic nanoplatform, gadolinium oxide-gold nanoclusters hybrid (Gd2O3-AuNCs), is constructed for multimodal imaging and drug delivery. The Gd2O3-AuNCs nanohybrid is developed by integrating Gd2O3 nanocrystals and gold nanoclusters into bovine serum albumin scaffold as a stabilizer. The nanohybrid exhibits favorable biocompatibility and is capable of enhancing the contrast in magnetic resonance and X-ray computed tomography imaging. Meanwhile, the integrated AuNCs component not only endows the nanohybrid to produce red fluorescence, but also sensitizes the generation of singlet oxygen ((1)O2) upon near-infrared laser stimulation at 808 nm...
March 1, 2017: ACS Applied Materials & Interfaces
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