Fluorescence Quenching of Uranine on Confeito-Like Au Nanoparticles

Ujihara, Masaki; Dang, Nhut Minh; Imae, Toyoko

doi:10.1166/jnn.2014.8712

Cited by 9 publications

(7 citation statements)

References 13 publications

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“…The internalization and cell localization of AuNPs was assessed by CLSM (Figure 4). The nuclei were stained with DAPI (cyan/blue fluorescence), while AuNP agglomerates (red) were observed by a fluorescent signal emitted by the bare AuNP due to their surface plasmon resonance at 525 nm 72. To ensure that there was no autofluorescence in cells, the emission spectrum was normalized with the ethanol-treated cells (control).…”

Section: Resultsmentioning

confidence: 99%

Gold nanoparticle uptake is enhanced by estradiol in MCF-7 breast cancer cells

Lara-Cruz

Jiménez-Salazar

Arteaga

et al. 2019

IJN

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Purpose: In the present study, we investigated the effects of 17β-estradiol (E 2 ) on membrane roughness and gold nanoparticle (AuNP) uptake in MCF-7 breast cancer cells. Methods: Estrogen receptor (ER)-positive breast cancer cells (MCF-7) were exposed to bare 20 nm AuNPs in the presence and absence of 1×10 −9 M E 2 for different time intervals for up to 24 hrs. The effects of AuNP incorporation and E 2 incubation on the MCF-7 cell surface roughness were measured using atomic force microscopy (AFM). Endocytic vesicle formation was studied using confocal laser scanning microscopy (CLSM). Finally, the results were confirmed by hyperspectral optical microscopy. Results: High-resolution AFM images of the surfaces of MCF-7 membranes (up to 250 nm 2 ) were obtained. The incubation of cells for 12 hrs with AuNP and E 2 increased the cell membrane roughness by 95% and 30% compared with the groups treated with vehicle (ethanol) or AuNPs only, respectively. This effect was blocked by an ER antagonist (7α,17β-[9-[(4,4,5,5,5-Pentafluoropentyl)sulfinyl]nonyl]estra-1,3,5(10)-triene-3,17-diol [ICI] 182,780). Higher amounts of AuNPs were localized inside MCF-7 cells around the nucleus, even after 6 hrs of E 2 incubation, compared with vehicle-treated cells. Endolysosome formation was induced by E 2 , which may be associated with an increase in AuNP-uptake. Conclusions: E 2 enhances AuNP incorporation in MCF-7 cells by modulating of plasma membrane roughness and inducing lysosomal endocytosis. These findings provide new insights into combined nanotherapies and hormone therapies for breast cancer.

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Section: Resultsmentioning

confidence: 99%

Gold nanoparticle uptake is enhanced by estradiol in MCF-7 breast cancer cells

Lara-Cruz

Jiménez-Salazar

Arteaga

et al. 2019

IJN

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“…The CAuNPs of two different sizes and the conventional spherical AuNPs were prepared as previously reported [ 43 , 44 , 45 , 46 ]. The average sizes of CAuNPs measured from TEM images were 100 and 50 nm ( Figure 1 A,B) for the preparation at low and high concentrations of citric acid, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…These AuNPs in dispersions had their specific plasmon absorption bands at 655 nm (100 nm CAuNPs), 590 nm (50 nm CAuNPs), and 530 nm (spherical AuNPs) ( Figure 2 ). The red-shifted plasmon absorption bands of the CAuNPs in dispersions suggest a convergence of the surface plasmon on the tips, which is caused by intra-particle interactions of surface plasmon on the surface of individual particle [ 26 , 43 , 44 , 45 , 46 ]. When the dispersions were concentrated to 5 mM/Au, the 50 nm CAuNPs showed a new broad absorption band around 800 nm in addition to the original plasmon adsorption band, although the 100 nm CAuNPs had the absorption band at the same position ( Figure 2 ).…”

Section: Resultsmentioning

confidence: 99%

“…In our study, the enhancing effects of non-spherical Au nanoparticles (AuNPs) were examined. The synthesis of confeito-like AuNPs (spherical AuNPs with many projections on their surfaces: CAuNPs) and their SERS effect have been reported in 2008 [ 42 ], and the synthesis method was improved in viewpoint of green chemistry and morphology control [ 43 , 44 , 45 , 46 ]. In the present study, the analytical enhancement factors of SERS were evaluated for the CAuNPs.…”

Section: Introductionmentioning

confidence: 99%

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Surface-Enhanced Resonance Raman Scattering of Rhodamine 6G in Dispersions and on Films of Confeito-Like Au Nanoparticles

Ujihara

Dang

Imae

2017

Sensors

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Surface-enhanced resonance Raman scattering (SERRS) of rhodamine 6G was measured on confeito-like Au nanoparticles (CAuNPs). The large CAuNPs (100 nm in diameter) in aqueous dispersion systems showed stronger enhancing effect (analytical enhancement factor: over 105) of SERRS than the small CAuNPs (50 nm in diameter), while the spherical Au nanoparticles (20 nm in diameter) displayed rather weak intensities. Especially, minor bands in 1400–1600 cm−1 were uniquely enhanced by the resonance effect of CAuNPs. The enhancement factors revealed a concentration dependence of the enhancing effect at low concentration of rhodamine 6G. This dependency was due to a large capacity of hot-spots on CAuNPs, which were formed without agglomeration. The surface-enhancing behaviour in the film systems was similar to that in the dispersions, although the large CAuNPs had lower enhancing effect in the films, and the small CAuNPs and the spherical Au nanoparticles were more effective in their films. These results suggest that the CAuNPs have an advantage in ultrasensitive devices both in dispersions and films, compared to the agglomerate of spherical Au nanoparticles.

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“…22 Fluorescence energy resonance transfer is the nonradiative transfer of energy from an excited donor fluorophore to an acceptor through nonradiative dipole-dipole coupling. 23 Since the efficiency of the energy transfer is inversely proportional to the sixth power of the distance between donor and acceptor, fluorescence energy resonance transfer only occurs when the distance of molecules is less than 10 nm. Based on the calculation (see Section 2.3), it was found that 1 ng of Fe 3 O 4 NPs can only adsorb 0.145 ng of AO, which was consistent with the result of Figure 2.…”

Section: Fluorescence Emission Intensity Of the Mixture Of Ao And Npsmentioning

confidence: 99%

Influence of Magnetic Fe3O4 Nanoparticles on Fluorescence Quenching of Dye Molecules

Zhang¹,

Su²,

Wang³

et al. 2016

j nanosci nanotechnol

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Magneto-fluorescent nanocomposites possessing both fluorescent and magnetic properties represent an attractive platform for biomedicine and nanotechnology. One of the great challenges facing magneto-fluorescent nanocomposites is understanding the influence of magnetic component on the fluorescence quenching of dye molecules. However, there was still lack of in-depth and quantitative analysis of fluorescence decay for magneto-fluorescent nanocomposites. Herein, fluorescence intensity decay of acridine orange, a model fluorescent dye, was quantitatively determined with magnetic Fe 3 O 4 nanoparticles in various concentrations ranging from 0 to 6250 ng · ml −1 . It was found that when the concentration of Fe 3 O 4 NPs was lower than 0.0625 ng · ml −1 , the fluorescence intensity decreased sharply with increasing concentration of Fe 3 O 4 NPs; when the NP concentrations ranged from 0.0625 ng · ml −1 to 1.25 ng · ml −1 , the fluorescence intensity of acridine orange decreased linearly with increase of NP concentration; and when the concentration of Fe 3 O 4 NPs exceeded 1.25 ng·ml −1 , essentially no fluorescence can be detected. These findings suggested that magneto-fluorescent composites with optimized fluorescence properties could be obtained by carefully controlling Fe 3 O 4 nanoparticle component, and offered a better understanding of interaction between magnetic NPs and luminescence of fluorescent molecules.

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Fluorescence Quenching of Uranine on Confeito-Like Au Nanoparticles

Cited by 9 publications

References 13 publications

<p>Gold nanoparticle uptake is enhanced by estradiol in MCF-7 breast cancer cells</p>

<p>Gold nanoparticle uptake is enhanced by estradiol in MCF-7 breast cancer cells</p>

Surface-Enhanced Resonance Raman Scattering of Rhodamine 6G in Dispersions and on Films of Confeito-Like Au Nanoparticles

Influence of Magnetic Fe<SUB>3</SUB>O<SUB>4</SUB> Nanoparticles on Fluorescence Quenching of Dye Molecules

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