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 In-Situ Gold–Ceria Nanoparticles: Superior Optical Fluorescence Quenching Sensor for Dissolved Oxygen

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 314 ◽  
Author(s):  
Nader Shehata ◽  
Ishac Kandas ◽  
Effat Samir
Keyword(s):  
Gold Nanoparticles ◽  
Fluorescence Quenching ◽  
Dissolved Oxygen ◽  
Optical Sensing ◽  
Fluorescence Emission ◽  
Water Quality Monitoring ◽  
Fluorescence Emission Spectrum ◽  
Ceria Nanoparticles ◽  
The Impact

Cerium oxide (ceria) nanoparticles (NPs) have been proved to be an efficient optical fluorescent material through generating visible emission (~530 nm) under violet excitation. This feature allowed ceria NPs to be used as an optical sensor via the fluorescence quenching Technique. In this paper, the impact of in-situ embedded gold nanoparticles (Au NPs) inside ceria nanoparticles was studied. Then, gold–ceria NPs were used for sensing dissolved oxygen (DO) in aqueous media. It was observed that both fluorescence intensity and lifetime were changed due to increased concentration of DO. Added gold was found to enhance the sensitivity of ceria to DO quencher detection. This enhancement was due to optical coupling between the fluorescence emission spectrum of ceria with the surface plasmonic resonance of gold nanoparticles. In addition, gold caused the decrease of ceria nanoparticles’ bandgap, which indicates the formation of more oxygen vacancies inside the non-stoichiometric crystalline structure of ceria. The Stern–Volmer constant, which indicates the sensitivity of optical sensing material, of ceria–gold NPs with added DO was found to be 893.7 M−1, compared to 184.6 M−1 to in case of ceria nanoparticles only, which indicates a superior optical sensitivity to DO compared to other optical sensing materials used in the literature to detect DO. Moreover, the fluorescence lifetime was found to be changed according to the variation of added DO concentration. The optically-sensitivity-enhanced ceria nanoparticles due to embedded gold nanoparticles can be a promising sensing host for dissolved oxygen in a wide variety of applications including biomedicine and water quality monitoring.

scholarly journals Highly stable noble metal nanoparticles dispersible in biocompatible solvents: synthesis of cationic phosphonium gold nanoparticles in water and DMSO

2016 ◽  
Vol 186 ◽  
pp. 77-93 ◽  
Author(s):  
Yon Ju-Nam ◽  
Wanisa Abdussalam-Mohammed ◽  
Jesus J. Ojeda
Keyword(s):  
Gold Nanoparticles ◽  
Drug Carrier ◽  
Aqueous Media ◽  
Noble Metal Nanoparticles ◽  
Great Opportunity ◽  
Thiolate Ligands ◽  
New Family ◽  
Uv Visible ◽  
Potential Use

In this work, we report the synthesis of novel cationic phosphonium gold nanoparticles dispersible in water and dimethyl sulfoxide (DMSO) for their potential use in biomedical applications. All the cationic-functionalising ligands currently reported in the literature are ammonium-based species. Here, the synthesis and characterisation of an alternative system, based on phosphonioalkylthiosulfate zwitterions and phosphonioalkylthioacetate were carried out. We have also demonstrated that our phosphonioalkylthiosulfate zwitterions readily disproportionate into phosphonioalkylthiolates in situ during the synthesis of gold nanoparticles produced by the borohydride reduction of gold(iii) salts. The synthesis of the cationic gold nanoparticles using these phosphonium ligands was carried out in water and DMSO. UV-visible spectroscopic and TEM studies have shown that the phosphonioalkylthiolates bind to the surface of gold nanoparticles which are typically around 10 nm in diameter. The resulting cationic-functionalised gold nanoparticles are dispersible in aqueous media and in DMSO, which is the only organic solvent approved by the U.S. Food and Drug Administration (FDA) for drug carrier tests. This indicates their potential future use in biological applications. This work shows the synthesis of a new family of phosphonium-based ligands, which behave as cationic masked thiolate ligands in the functionalisation of gold nanoparticles. These highly stable colloidal cationic phosphonium gold nanoparticles dispersed in water and DMSO can offer a great opportunity for the design of novel biorecognition and drug delivery systems.

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.

Significant sensitivity and stability enhancement of tetraphenylporphyrin-based optical oxygen sensing material in presence of perfluorochemicals

2013 ◽  
Vol 17 (06n07) ◽  
pp. 431-439 ◽  
Author(s):  
Sevinc Z. Topal ◽  
Emel Önal ◽  
Kadriye Ertekin ◽  
Ozlem Oter ◽  
Ayşe G. Gürek ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Oxygen Sensing ◽  
Intensity Variation ◽  
Oxygen Sensitivity ◽  
Regeneration Time ◽  
Sensing Material ◽  
Response Range ◽  
Stability Enhancement ◽  
Volmer Constant

Emission-based oxygen sensing properties of highly luminescent tetraphenylporphyrin molecules were investigated in polystyrene, ethyl cellulose, poly(1-trimethylsilyl-1-propyne) and poly(isobutylmethacrylate) matrices. The effect of perfluorochemicals (PFCs) on oxygen sensitivity and stability of the sensor materials was also examined. Fluorescence intensity and lifetime measurements of meso-tetraphenylporphyrinato Zn ( II ) (ZnTPP) and meso-tetraphenylporphyrin (H2TPP) materials were performed in the concentration range of 0–100% pO 2. The fluorescence intensity variation of H2TPPvs. oxygen was 86%. H2TPP-based composite also yielded higher Stern–Volmer constant, faster response and regeneration time, excellent long term photostability and larger linear response range with respect to ZnTPP. The detection limit of oxygen for H2TPP was less than 0.5%. When stored in sealed bags protected from sunlight, no decrease in oxygen sensitivity was observed during approximately five months. As far as we know, the gathered utilization of PFCs and H2TPP embedded in polymer matrices was not previously described in literature, and has present amelioration compared to materials already existing.

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,...

scholarly journals Correction: Poly(adenine)-mediated DNA-functionalized gold nanoparticles for sensitive detection of mercury ions in aqueous media

RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 22691-22691
Author(s):  
Jinjin Yin ◽  
Jiuchao Wang ◽  
Xiyue Yang ◽  
Tao Wu ◽  
Huashan Wang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Media ◽  
Sensitive Detection ◽  
Mercury Ions ◽  
Functionalized Gold Nanoparticles

Correction for ‘Poly(adenine)-mediated DNA-functionalized gold nanoparticles for sensitive detection of mercury ions in aqueous media’ by Jinjin Yin et al., RSC Adv., 2019, 9, 18728–18733, DOI: 10.1039/C9RA03041G.

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...

Roughened gold electrode for in situ SERS analysis of structural changes accompanying the doping process of polyaniline in acidic aqueous media

2021 ◽  
Vol 882 ◽  
pp. 115034
Author(s):  
A. El Guerraf ◽  
M. Bouabdallaoui ◽  
Z. Aouzal ◽  
S. Ben Jadi ◽  
N.K. Bakirhan ◽  
...  
Keyword(s):  
Gold Electrode ◽  
Structural Changes ◽  
Aqueous Media
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