scholarly journals Gold/QDs-Embedded-Ceria Nanoparticles: Optical Fluorescence Enhancement as a Quenching Sensor

2020 ◽  
Vol 10 (4) ◽  
pp. 1236
Author(s):  
Nader Shehata ◽  
Effat Samir ◽  
Ishac Kandas
Keyword(s):  
Fluorescence Intensity ◽  
Pollution Monitoring ◽  
Plasmonic Nanostructures ◽  
Ceria Nanoparticles ◽  
Optical Coupling ◽  
Plasmonic Resonance ◽  
Cdse Qds ◽  
Fluorescence Excitation ◽  
Au Nps

This work focuses on improving the fluorescence intensity of cerium oxide (ceria) nanoparticles (NPs) through added plasmonic nanostructures. Ceria nanoparticles are fluorescent nanostructures which can emit visible fluorescence emissions under violet excitation. Here, we investigated different added plasmonic nanostructures, such as gold nanoparticles (Au NPs) and Cadmium sulfide/selenide quantum dots (CdS/CdSe QDs), to check the enhancement of fluorescence intensity emissions caused by ceria NPs. Different plasmonic resonances of both aforementioned nanostructures have been selected to develop optical coupling with both fluorescence excitation and emission wavelengths of ceria. In addition, different additions whether in-situ or post-synthesis have been investigated. We found that in-situ Au NPs of a 530 nm plasmonic resonance wavelength provides the highest fluorescence emissions of ceria NPs compared to other embedded plasmonic structures. In addition to the optical coupling between plasmonic resonance of Au with the visible emissions fluorescence spectrum of ceria nanoparticles, the 530 nm in-situ Au NPs were found to reduce the bandgap of ceria NPs. We suggest that the formation of more tri-valent cerium ions traps energy levels along with more associated oxygen vacancies, which is responsible for increasing the fluorescence visible emissions intensity caused by ceria. As an application, the gold-ceria NPs is shown to optically detect the varied concentration of iron tiny particles in aqueous medium based on a fluorescence quenching mechanism. This work is promising in different applications such as biomarkers, cancer treatments, and environmental pollution monitoring.

scholarly journals Plasmonic-Ceria Nanoparticles as Fluorescence Intensity and Lifetime Quenching Optical Sensor

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2818
Author(s):  
Nader Shehata ◽  
Effat Samir ◽  
Ishac Kandas
Keyword(s):  
Gold Nanoparticles ◽  
Fluorescence Intensity ◽  
Aqueous Media ◽  
Fluorescence Emission ◽  
Intensity Change ◽  
Ceria Nanoparticles ◽  
Trivalent Cerium ◽  
Sensing Material ◽  
Volmer Constant

Ceria nanoparticles have been recently used as an optical fluorescent material with visible emission under ultraviolet excitation, due to the formation of trivalent cerium ions with corresponding oxygen vacancies. This paper introduces the enhancement of both fluorescence emission and lifetime through adding gold nanoparticles. The reason is due to possible coupling between the plasmonic resonance of gold nanoparticles and the fluorescence emission of ceria that has been achieved, along with enhanced formation of trivalent cerium ions. Both factors lead to higher fluorescence intensity peaks and shorter fluorescence lifetimes. As an application, gold-ceria nanoparticles have been used as an optical sensing material for lead particles in aqueous media based on fluorescence quenching. Stern-Volmer constant of in-situ gold-ceria nanoparticles is found to be 2.424 M−1, with a relative intensity change of up to 40% at 0.2 g/L.

scholarly journals Easy and fast in-situ functionalization of exfoliated 2D black phosphorus with gold nanoparticles

2021 ◽  
Author(s):  
Salvatore Moschetto ◽  
Andrea Ienco ◽  
Gabriele Manca ◽  
Manuel Serrano-Ruiz ◽  
Maurizio Peruzzini ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Black Phosphorus ◽  
Au Nps ◽  
In Situ Functionalization

Heterostructures of single- and few-layer black phosphorus (2D bP) functionalized with gold nanoparticles (Au NPs) have been recently reported in the literature, exploiting their intriguing properties and biocompatibility for catalytic,...

Macroscopical monolayer films of ordered arrays of gold nanoparticles as SERS substrates for in-situ quantitative detection in aqueous solutions

Nanoscale ◽  
2021 ◽  
Author(s):  
Lixiang Xing ◽  
Cui Wang ◽  
Yi Cao ◽  
Jihui Zhang ◽  
Haibing Xia
Keyword(s):  
Gold Nanoparticles ◽  
Volume Fraction ◽  
Water Volume ◽  
Quantitative Detection ◽  
Monolayer Films ◽  
Au Nps ◽  
Sers Substrates ◽  
Ordered Arrays ◽  
Water Volume Fraction

In this work, macroscopical monolayer films of ordered arrays of gold nanoparticles (MMF-OA-Au NPs) are successfully prepared at the interfaces of toluene-diethylene glycol (DEG) with a water volume fraction of...

scholarly journals Improved In Situ Hybridization Efficiency with Locked-Nucleic-Acid-Incorporated DNA Probes

2006 ◽  
Vol 72 (8) ◽  
pp. 5311-5317 ◽  
Author(s):  
Kengo Kubota ◽  
Akiyoshi Ohashi ◽  
Hiroyuki Imachi ◽  
Hideki Harada
Keyword(s):  
In Situ Hybridization ◽  
Nucleic Acid ◽  
Fluorescence Intensity ◽  
Dna Probes ◽  
Locked Nucleic Acid ◽  
Factors Affecting ◽  
Hybridization Efficiency ◽  
Probe Hybridization ◽  
Major Factors

ABSTRACT Low signal intensity due to poor probe hybridization efficiency is one of the major drawbacks of rRNA-targeted in situ hybridization. There are two major factors affecting the hybridization efficiency: probe accessibility and affinity to the targeted rRNA molecules. In this study, we demonstrate remarkable improvement in in situ hybridization efficiency by applying locked-nucleic-acid (LNA)-incorporated oligodeoxynucleotide probes (LNA/DNA probes) without compromising specificity. Fluorescently labeled LNA/DNA probes with two to four LNA substitutions exhibited strong fluorescence intensities equal to or greater than that of probe Eub338, although these probes did not show bright signals when they were synthesized as DNA probes; for example, the fluorescence intensity of probe Eco468 increased by 22-fold after three LNA bases were substituted for DNA bases. Dissociation profiles of the probes revealed that the dissociation temperature was directly related to the number of LNA substitutions and the fluorescence intensity. These results suggest that the introduction of LNA residues in DNA probes will be a useful approach for effectively enhancing probe hybridization efficiency.

Karyotypes and Distribution of Tandem Repeat Sequences in Brassica nigra Determined by Fluorescence in situ Hybridization

2017 ◽  
Vol 152 (3) ◽  
pp. 158-165 ◽  
Author(s):  
Gui-xiang Wang ◽  
Qun-yan He ◽  
Jiri Macas ◽  
Petr Novák ◽  
Pavel Neumann ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Fluorescence Intensity ◽  
Tandem Repeat ◽  
Brassica Nigra ◽  
Metaphase Chromosomes ◽  
Repeat Sequences ◽  
Tandem Repeat Sequences ◽  
Black Mustard

Whole-genome shotgun reads were analyzed to determine the repeat sequence composition in the genome of black mustard, Brassica nigra (L.) Koch. The analysis showed that satellite DNA sequences are very abundant in the black mustard genome. The distribution pattern of 7 new tandem repeats (BnSAT13, BnSAT28, BnSAT68, BnSAT76, BnSAT114, BnSAT180, and BnSAT200) on black mustard chromosomes was visualized using fluorescence in situ hybridization (FISH). The FISH signals of BnSAT13 and BnSAT76 provided useful cytogenetic markers; their position and fluorescence intensity allowed for unambiguous identification of all 8 somatic metaphase chromosomes. A karyotype showing the location and fluorescence intensity of these tandem repeat sequences together with the position of rDNAs and centromeric retrotransposons of Brassica (CRB) was constructed. The establishment of the FISH-based karyotype in B. nigra provides valuable information that can be used in detailed analyses of B. nigra accessions and derived allopolyploid Brassica species containing the B genome.

In situ formation of luminescent CdSe QDs in a metallohydrogel: a strategy towards synthesis, isolation, storage and re-dispersion of the QDs

Nanoscale ◽  
2017 ◽  
Vol 9 (36) ◽  
pp. 13820-13827 ◽  
Author(s):  
Sayantan Chatterjee ◽  
Uday Maitra
Keyword(s):  
Organic Solvent ◽  
Bile Salt ◽  
Room Temperature ◽  
Cdse Qds ◽  
One Step ◽  
In Situ Formation

We describe a practical, one step, room temperature in situ synthesis of luminescent CdSe QDs using a bile salt derived metallogel, followed by their isolation from the gel and re-dispersion in an organic solvent.

A novel photoelectrode based on eosin Y–rhodamine B duo-dye sensitized Au nanoparticles by in situ reduction

2017 ◽  
Vol 9 (38) ◽  
pp. 5586-5592 ◽  
Author(s):  
Y. L. Yuan ◽  
G. M. Pang ◽  
X. K. Li ◽  
W. Y. Zhu ◽  
H. C. Pan
Keyword(s):  
Rhodamine B ◽  
Au Nanoparticles ◽  
Specific Response ◽  
Eosin Y ◽  
In Situ Reduction ◽  
Au Nps ◽  
Dye Sensitized ◽  
Novel Strategy

A novel strategy for the fabrication of a photoelectrochemical system, involving a duo-dye sensitized Au NPs composite, that displays a specific response to mercury.

Au-on-Ag nanostructure for in-situ SERS monitoring of catalytic reactions

2022 ◽  
Author(s):  
Shuyue He ◽  
Di Wu ◽  
Siwei Chen ◽  
Kai Liu ◽  
Eui-Hyeok Yang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Thermal Evaporation ◽  
Reduction Process ◽  
Ag Nps ◽  
Au Nps ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Raman Probe

Abstract Dual-functionality Au-on-Ag nanostructures (AOA) were fabricated on a silicon substrate by first immobilizing citrate-reduced Ag nanoparticles (Ag NPs, ~43 nm in diameter), followed by depositing ~7 nm Au nanofilms (Au NFs) via thermal evaporation. Au NFs were introduced for their catalytic activity in concave-convex nano-configuration. Ag NPs underneath were used for their significant enhancement factor (EF) in surface-enhanced Raman scattering (SERS)-based measurements of analytes of interest. Rhodamine 6G (R6G) was utilized as the Raman-probe to evaluate the SERS sensitivity of AOA. The SERS EF of AOA is ~37 times than that of Au NPs. Using reduction of 4-nitrothiophenol (4-NTP) by sodium borohydride (NaBH4) as a model reaction, we demonstrated the robust catalytic activity of AOA as well as its capacity to continuously monitor via SERS the disappearance of reactant 4-NTP, emergence and disappearance of intermediate 4, 4’-DMAB, and the appearance of product 4-ATP throughout the reduction process in real-time and in situ.

scholarly journals Real-time synthesis and detection of plasmonic metal (Au, Ag) nanoparticles under monochromatic X-ray nano-tomography

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Amardeep Bharti ◽  
Keun Hwa Chae ◽  
Navdeep Goyal
Keyword(s):  
Particle Size ◽  
Real Time ◽  
Reduction Process ◽  
Localized Surface Plasmon ◽  
Plasmonic Nanostructures ◽  
X Rays ◽  
X Ray ◽  
The Real ◽  
Size And Shape

AbstractPlasmonic nanostructures are of immense interest of research due to its widespread applications in microelectronics, photonics, and biotechnology, because of its size and shape-dependent localized surface plasmon resonance response. The great efforts have been constructed by physicists, chemists, and material scientists to deliver optimized reaction protocol to tailor the size and shape of nanostructures. Real-time characterization emerges out as a versatile tool in perspective to the optimization of synthesis parameters. Moreover, in the past decades, radiation-induced reduction of metallic-salt to nanoparticles dominates over the conventional direct chemical reduction process which overcomes the production of secondary products and yields ultra-high quality and pure nanostructures. Here we show, the real-time/in-situ synthesis and detection of plasmonic (Au andAg) nanoparticles using single synchrotron monochromatic 6.7 keV X-rays based Nano-Tomography beamline. The real-time X-ray nano-tomography of plasmonic nanostructures has been first-time successfully achieved at such a low-energy that would be leading to the possibility of these experiments at laboratory-based sources. In-situ optical imaging confirms the radiolysis of water molecule resulting in the production of $$e_{aq}^-,\,OH^\bullet ,$$ e aq - , O H ∙ , and $$O_2^-$$ O 2 - under X-ray irradiation. The obtained particle-size and size-distribution by X-ray tomography are in good agreement to TEM results. The effect of different chemical environment media on the particle-size has also been studied. This work provides the protocol to precisely control the size of nanostructures and to synthesize the ultrahigh-purity grade monodisperse nanoparticles that would definitely enhance the phase-contrast in cancer bio-imaging and plasmonic photovoltaic application.

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