Luminescence quantum yields of gold nanoparticles varying with excitation wavelengths

Nanoscale ◽  
2016 ◽  
Vol 8 (4) ◽  
pp. 2188-2194 ◽  
Author(s):  
Yuqing Cheng ◽  
Guowei Lu ◽  
Yingbo He ◽  
Hongming Shen ◽  
Jingyi Zhao ◽  
...  

The photoluminescence quantum yields of gold nanoparticles, nanorods and nanobipyramids are excitation wavelength dependent.

2017 ◽  
Author(s):  
Yuqing Cheng ◽  
Yingbo He ◽  
Jingyi Zhao ◽  
Hongming Shen ◽  
Keyu Xia ◽  
...  

Nano Letters ◽  
2011 ◽  
Vol 11 (7) ◽  
pp. 2725-2730 ◽  
Author(s):  
Keiko Munechika ◽  
Yeechi Chen ◽  
Andreas F. Tillack ◽  
Abhishek P. Kulkarni ◽  
Ilan Jen-La Plante ◽  
...  

2019 ◽  
Vol 9 (20) ◽  
pp. 4300
Author(s):  
Paerhatijiang Tuersun ◽  
Xiayiding Yakupu ◽  
Xiang’e Han ◽  
Yingzeng Yin

Previous investigations devoted to the optimization of nonspherical gold nanoparticles for photothermal therapy (PTT) encountered two issues, namely, the appropriate selection of objective functions and the processing of particle random orientations. In this study, these issues were resolved, and accurate optimization results were obtained for the three typical nonspherical gold nanoparticles (nanospheroid, nanocylinder, and nanorod) by using the T-matrix method. The dependence of the optimization results on the excitation wavelength and the refractive index of tissue was investigated. Regardless of the excitation wavelength and tissue type, gold nanospheroids were found to be the most effective therapeutic agents for PTT. The light absorption ability of optimized nanoparticles could be enhanced by using a laser with a longer wavelength. Finally, the design tolerance for the different sizes of nanoparticles was provided.


2017 ◽  
Vol 5 (3) ◽  
pp. 187 ◽  
Author(s):  
Jinghuan Yang ◽  
Quan Sun ◽  
Han Yu ◽  
Kosei Ueno ◽  
Hiroaki Misawa ◽  
...  

2017 ◽  
Vol 46 ◽  
pp. 234-240
Author(s):  
Wen Juan Dong ◽  
Ji Yan Han ◽  
Xin Wu ◽  
Li Fan ◽  
Wen Ting Liang

A novel near-infrared fluorescence quenching method has been developed for the determination of hydrogen peroxide based on N-acetyl-L-cysteine-capped gold nanoparticles (NAC-AuNPs) as a fluorescence probe. The prepared gold nanoparticles with the size of about 1.91 nm exhibited strong near-infrared fluorescence emission at 693 nm with excitation wavelength at 450 nm in aqueous solution. The fluorescence intensity of NAC-AuNPs was quenched dramatically by adding hydrogen peroxide. Therefore, it could be used to detect hydrogen peroxide based on the fluorescence quenching intensity was linear with the concentration of hydrogen peroxide. Under the optimal experimental conditions, the linear range and detection limit were 1.0×10-6 –3.0×10-2 mol/L and 1.0×10-7 mol/L, respectively. The possible quenching mechanism was investigated by time-resolved fluorescence spectroscopy. The proposed method was simple, sensitive and showed good repeatability and stability.


MRS Advances ◽  
2017 ◽  
Vol 2 (51) ◽  
pp. 2927-2934 ◽  
Author(s):  
Zhoufeng Jiang ◽  
Marta J. Krysmann ◽  
Antonios Kelarakis ◽  
Petr Koutnik ◽  
Pavel Anzenbacher ◽  
...  

ABSTRACTThe carbon dots were investigated to reveal their light-emitting mechanism. The fluorescence spectra of carbon dots show typically two different types of photoluminescence: the excitation-independent component in the short wavelength, and the excitation-dependent component in the longer wavelength. The UV-Vis spectrum of carbon dots shows the absorption maximum of 340 nm which should be accredited to the n-π* transition of the carbonyl group in carbon dots. Absolute quantum yields of carbon dots dispersed in Polyvinyl alcohol is around 15% when the excitation wavelength is less than 425 nm, but decreases continuously when the excitation wavelength increases. The decay lifetimes of the carbon dots also show an abrupt change at excitation wavelength 425 nm. Time resolved photoluminescence was implemented from 31K to 291K to study the photoluminescence decay dynamics of carbon dots, resulting in the continuously decreasing of the lifetime as the temperature increases.


2018 ◽  
Vol 71 (11) ◽  
pp. 882 ◽  
Author(s):  
Buhong Gao ◽  
Yu Sun ◽  
Yingchun Miao ◽  
Huihua Min ◽  
Li Xu ◽  
...  

Highly luminescent nitrogen-doped carbonaceous nanospheres (LNCNs) were synthesized by a one-pot hydrothermal reaction of β-cyclodextrin (β-CD) and branched polyethylenimine (BPEI). Both the N-doping and amino-functionalisation of LNCNs were achieved simultaneously. The prepared LNCNs display excellent properties such as high physical and chemical stability, excitation wavelength-independent emission, and high photoluminescence quantum yields. Importantly, the LNCNs exhibit a quenching of photoluminescence in the presence of quercetin (Qc) based on the simple static quenching mechanism, making it possible to quantify concentrations from 0.5 to 80 μg mL−1 with a detection limit of 0.21 μg mL−1. Furthermore, the LNCNs probe was further used for imaging Qc in living cells.


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