Browse
Submit Data
Databases
API
Help

Dataset Information

35 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Fluorescent Polyelectrolyte Capped Silver Nanoclusters: Optimization and Spectroscopic Evaluation.

ABSTRACT: In the present work, we have synthesized water soluble Ag nanoclusters using PMAA as a template with different Ag+: COO-ratios, to optimize it for highest brightness using less UV exposure time. Fluorescence polarization was 0.30 for and was found to vary with excitation and emission wavelength with few hundred picoseconds average fluorescence lifetime. Fluorescence Correlation Spectroscopy data depicts slower diffusion at red excitation compared to blue excitation in confocal volume than conventionally synthesized colloids proving presence of multiple sizes. The optical properties of the particles are dependent upon the excitation wavelength used and the emission wavelength collected.

SUBMITTER: Raut S

PROVIDER: S-EPMC3678839 | biostudies-literature | 2012 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Fluorescent Polyelectrolyte Capped Silver Nanoclusters: Optimization and Spectroscopic Evaluation.

Raut Sangram S Rich Ryan R Akopova Irina I Thyrhaug Erling E Shtoyko Tanya T Shumilov Dimytro D Gryczynski Zygmunt Z Gryczynski Ignacy I

Chemical physics letters 20121001

In the present work, we have synthesized water soluble Ag nanoclusters using PMAA as a template with different Ag+: COO-ratios, to optimize it for highest brightness using less UV exposure time. Fluorescence polarization was 0.30 for and was found to vary with excitation and emission wavelength with few hundred picoseconds average fluorescence lifetime. Fluorescence Correlation Spectroscopy data depicts slower diffusion at red excitation compared to blue excitation in confocal volume than conven ...[more]

PMID: 23772092

Similar Datasets

Polyethyleneimine Capped Silver Nanoclusters as Efficient Antibacterial Agents.

Project description:Development of efficient antibacterial agents is critical for human health. In the present study, we investigated the antibacterial activity of polyethyleneimine (PEI)-capped silver nanoclusters (PEI-AgNCs), based on the fact that nanoclusters normally have higher surface-to-volume ratios than traditional nanomaterials and PEI itself has a strong antimicrobial capacity. We synthesized stable silver nanoclusters by altering PEI molecular weight from 0.6 kDa to 25 kDa and characterized them by UV-Vis absorption and fluorescence spectroscopy and high resolution transmission electron microscopy. The sizes of AgNCs were around 2 nm in diameter and were little influenced by the molecular weight of PEIs. The antibacterial abilities of the four PEI-AgNCs were explored on agar plate and in liquid systems. Our results revealed that the antibacterial activity of PEI-AgNCs is excellent and the reduction of PEI molecular weight could result in the increased antibacterial capacity of PEI-AgNCs. Such proposed new materials might be useful as efficient antibacterial agents in practical clinical applications.

| S-EPMC4808997 | biostudies-literature

Polyethyleneimine-capped silver nanoclusters for microRNA oligonucleotide delivery and bacterial inhibition.

Project description:Efficient and safe nonviral gene delivery systems are a prerequisite for the clinical application of therapeutic genes. In this paper, polyethyleneimine-capped silver nanoclusters (PEI-AgNCs) were prepared for the purpose of microRNA (miRNA) delivery. The resultant PEI-AgNCs were characterized by a photoluminescence assay and transmission electron microscopy. A cytotoxicity assay showed that PEI-AgNCs exhibit relatively low cytotoxicity. Interestingly, PEI-AgNCs were confirmed to transfect miRNA mimics more effectively than PEI in HepG2 and 293A cells. In this regard, hsa-miR-21 or hsa-miR-221 mimics (miR-21/221m) were transported into HepG2 cells by using PEI-AgNCs. The miR-21/221 expression was determined post-transfection by quantitative real-time polymerase chain reaction. Compared with the negative control, PEI-AgNCs/miR-21/221m groups exhibited higher miR-21/221 levels. In addition, AgNCs endow PEI with stronger antibacterial activity, and this advantage provided PEI-AgNCs the potential to prevent bacterial contamination during the transfection process. Furthermore, we showed that PEI-AgNCs are viable nanomaterials for plain imaging of the cells by laser scanning confocal microscopy, indicating great potential as an ideal fluorescent probe to track the transfection behavior. These results demonstrated that PEI-AgNCs are promising and novel nonviral vectors for gene delivery.

| S-EPMC5716333 | biostudies-literature

Phosphorothioate DNA Stabilized Fluorescent Gold and Silver Nanoclusters.

Project description:Unmodified single-stranded DNA has recently gained popularity for the templated synthesis of fluorescent noble metal nanoclusters (NCs). Bright, stable, and biocompatible clusters have been developed primarily through optimization of DNA sequence. However, DNA backbone modifications have not yet been investigated. In this work, phosphorothioate (PS) DNAs are evaluated in the synthesis of Au and Ag nanoclusters, and are employed to successfully template a novel emitter using T15 DNA at neutral pH. Mechanistic studies indicate a distinct UV-dependent formation mechanism that does not occur through the previously reported thymine N3. The positions of PS substitution have been optimized. This is the first reported use of a T15 template at physiological pH for AgNCs.

| S-EPMC5312886 | biostudies-literature

Silver Nanoparticle-Mediated Synthesis of Fluorescent Thiolated Gold Nanoclusters.

Project description:A new strategy using silver nanoparticles (Ag NPs) to synthesize thiolated Au NCs is demonstrated. The quasi-spherical Ag NPs serve as a platform, functioning as a reducing agent for Au (III) and attracting capping ligands to the surface of the Ag NPs. Glutathione disulfide (GSSG) and dithiothreitol (DTT) were used as capping ligands to synthesize thiolated Au NCs (glutathione-Au NCs and DTT-Au NCs). The glutathione-Au NCs and DTT-Au NCs showed red color luminance with similar emission wavelengths (630 nm) at an excitation wavelength of 354 nm. The quantum yields of the glutathione-Au NCs and DTT-Au NCs were measured to be 7.3% and 7.0%, respectively. An electrophoretic mobility assay showed that the glutathione-Au NCs moved toward the anode, while the DTT-Au NCs were not mobile under the electric field, suggesting that the total net charge of the thiolated Au NCs is determined by the charges on the capping ligands. The detection of the KSV values, 26 M-1 and 0 M-1, respectively, revealed that glutathione-Au NCs are much more accessible to an aqueous environment than DTT-Au NCs.

| S-EPMC8624127 | biostudies-literature

In vitro and intracellular production of peptide-encapsulated fluorescent silver nanoclusters.

Project description: Not available

| S-EPMC2754274 | biostudies-literature

Sub-micron scale patterning of fluorescent silver nanoclusters using low-power laser.

Project description:Noble metal nanoclusters are ultrasmall nanomaterials with tunable properties and huge application potential; however, retaining their enhanced functionality is difficult as they readily lose their properties without stabilization. Here, we demonstrate a facile synthesis of highly photostable silver nanoclusters in a polymer thin film using visible light photoreduction. Furthermore, the different stages of the nanocluster formation are investigated in detail using absorption and fluorescence spectroscopy, fluorescence microscopy, and atomic force microscopy. A cost-effective fabrication of photostable micron-sized fluorescent silver nanocluster barcode is demonstrated in silver-impregnated polymer films using a low-power continuous-wave laser diode. It is shown that a laser power of as low as 0.75 mW is enough to write fluorescent structures, corresponding to the specifications of a commercially available laser pointer. The as-formed nanocluster-containing microstructures can be useful in direct labeling applications such as authenticity marking and fluorescent labeling.

| S-EPMC4820741 | biostudies-literature

Turn-on fluorescent nanoprobe for ATP detection based on DNA-templated silver nanoclusters.

Project description:A turn-on fluorescence nanoprobe was constructed for the determination of adenosine 5'-triphosphate (ATP) based on DNA-templated silver nanoclusters (DNA-AgNCs). The significant enhancement fluorescence intensity of DNA-AgNCs in the presence of ATP is due to the high special binding affinity between ATP and the aptamer, resulting in the environment of DNA-AgNCs with darkish fluorescence lying at one terminus of DNA slightly altering owing to the change of ATP aptamer conformation. A good linear range runs from 9 to 24 mM with a satisfactory detection limit of 3 μM. Furthermore, the proposed nanoprobe exhibited good performance for ATP detection in diluted fetal bovine serum.

| S-EPMC10863603 | biostudies-literature

Toward site-specific, homogeneous and highly stable fluorescent silver nanoclusters fabrication on triplex DNA scaffolds.

Project description:A new strategy to create site-specific, homogeneous, and bright silver nanoclusters (AgNCs) with high-stability was demonstrated by triplex DNA as template. By reasonable design of DNA sequence, homogeneous Ag(2) cluster was obtained in the predefined position of CG.C(+) site of triplex DNA. This strategy was also explored for controlled alignment of AgNCs on the DNA nanoscaffold. To the best of our knowledge, this was the first example to simultaneously answer the challenges of excellent site-specific nucleation and growth, homogeneity and stability against salt of DNA-templated AgNCs.

| S-EPMC3439878 | biostudies-other

DNA-Templated Fluorescent Silver Nanoclusters Inhibit Bacterial Growth While Being Non-Toxic to Mammalian Cells.

Project description:Silver has a long history of antibacterial effectiveness. The combination of atomically precise metal nanoclusters with the field of nucleic acid nanotechnology has given rise to DNA-templated silver nanoclusters (DNA-AgNCs) which can be engineered with reproducible and unique fluorescent properties and antibacterial activity. Furthermore, cytosine-rich single-stranded DNA oligonucleotides designed to fold into hairpin structures improve the stability of AgNCs and additionally modulate their antibacterial properties and the quality of observed fluorescent signals. In this work, we characterize the sequence-specific fluorescence and composition of four representative DNA-AgNCs, compare their corresponding antibacterial effectiveness at different pH, and assess cytotoxicity to several mammalian cell lines.

| S-EPMC8271471 | biostudies-literature

Unraveling the molecular mechanism of photosynthetic toxicity of highly fluorescent silver nanoclusters to Scenedesmus obliquus.

Project description:While the discovery of numerous attractive properties of silver at the nanoscale has increased their demand in many sectors including medicine, optics, sensing, painting and cosmetics, it has also raised wide public concerns about their effect on living organisms in aquatic environment. Despite the continuous effort to understand the various aspects of the toxicity of silver nanomaterials, the molecular level understanding on their cytotoxicity mechanism to biological organisms has remained unclear. Herein, we demonstrated the underlying mechanism of the photosynthetic toxicity against green algae namely, Scenedesmus obliquus by using an emerging silver nanomaterial, called silver nanoclusters (defined as r-Ag NCs). By exploiting the unique fluorescence properties of r-Ag NCs along with various other analytical/biological tools, we proposed that the photosynthetic toxicity of r-Ag NCs was largely attributed to the "joint-toxicity" effect of particulate form of r-Ag NCs and its released Ag+, which resulted in the disruption of the electron transport chain of light reaction and affected the content of key enzymes (RuBP carboxylase/ oxygenase) of Calvin cycle of algae cells. We believe that the present study can also be applied to the assessment of the ecological risk derived from other metal nanoparticles.

| S-EPMC5703894 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data