A new fluorescent sensor for detecting p-nitrophenol based on β-cyclodextrin-capped ZnO quantum dots

RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 86061-86067 ◽  
Author(s):  
Shuo Geng ◽  
Shu Min Lin ◽  
Shi Gang Liu ◽  
Nian Bing Li ◽  
Hong Qun Luo
Keyword(s):  
Quantum Dots ◽  
Fluorescent Sensor ◽  
Water Soluble ◽  
Quenching Mechanism ◽  
Zno Quantum Dots ◽  
Zno Qds

Water-soluble fluorescent β-cyclodextrin-capped ZnO QDs were synthesized and used to detect p-NP, and the quenching mechanism was discussed.

scholarly journals Synthesis and Characterization of Polyvinylpyrrolidone-Modified ZnO Quantum Dots and Their In Vitro Photodynamic Tumor Suppressive Action

2021 ◽  
Vol 22 (15) ◽  
pp. 8106
Author(s):  
Tianming Song ◽  
Yawei Qu ◽  
Zhe Ren ◽  
Shuang Yu ◽  
Mingjian Sun ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Photodynamic Therapy ◽  
Inhibitory Effect ◽  
Therapeutic Effects ◽  
In Vivo Experiments ◽  
Potential Applications ◽  
Zno Quantum Dots ◽  
Zno Qds

Despite the numerous available treatments for cancer, many patients succumb to side effects and reoccurrence. Zinc oxide (ZnO) quantum dots (QDs) are inexpensive inorganic nanomaterials with potential applications in photodynamic therapy. To verify the photoluminescence of ZnO QDs and determine their inhibitory effect on tumors, we synthesized and characterized ZnO QDs modified with polyvinylpyrrolidone. The photoluminescent properties and reactive oxygen species levels of these ZnO/PVP QDs were also measured. Finally, in vitro and in vivo experiments were performed to test their photodynamic therapeutic effects in SW480 cancer cells and female nude mice. Our results indicate that the ZnO QDs had good photoluminescence and exerted an obvious inhibitory effect on SW480 tumor cells. These findings illustrate the potential applications of ZnO QDs in the fields of photoluminescence and photodynamic therapy.

Studies on Optical Properties of CdS/ZnO Quantum Dots Prepared by Sol-Gel Method

2011 ◽  
Vol 364 ◽  
pp. 129-133 ◽  
Author(s):  
Liyana Mohd Lawi Ruhana ◽  
Taqiyuddin Mawardi Ayob Muhammad ◽  
Radiman Shahidan ◽  
Irman Abdul Rahman ◽  
Bohari M. Yamin
Keyword(s):  
Quantum Dots ◽  
Sol Gel ◽  
Emission Spectra ◽  
Blue Shift ◽  
Mixture Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Zno Quantum Dots ◽  
Zno Qds

CdS/ZnO quantum dots (QDs) were prepared at a temperature of 293 K by the sol-gel method with Triethanolamine (TEA) as a capping agent. The effect of CdS/ZnO mixture ratio of 1:9, 1:1 and 9:1 on the optical absorption and fluorescence spectra were investigated by UV-Vis and Fluorescence spectroscopy. By increasing ZnO composition, a blue-shift of absorption edge and emission spectra were observed. The band gap for 1:9, 1:1 and 9:1 were found to be 4.13, 3.93 and 3.11 eV, respectively. The morphology of the CdS/ZnO QDs for each mixing ratio was obtained by transmission electron microscope (TEM). The size of the QDs was found to be in the range of 5-10 nm with some agglomerated particles.

ZnO quantum dots and graphene based heterostructure for excellent photoelastic and highly sensitive ultraviolet photodetector

RSC Advances ◽  
2015 ◽  
Vol 5 (110) ◽  
pp. 90838-90846 ◽  
Author(s):  
Buddha Deka Boruah ◽  
Abha Misra
Keyword(s):  
Quantum Dots ◽  
Zinc Oxide ◽  
Ultraviolet Photodetector ◽  
Highly Sensitive ◽  
Zno Quantum Dots ◽  
Ultraviolet Photodetectors ◽  
Zno Qds

Heterostructures comprised of zinc oxide quantum dots (ZnO QDs) and graphene are presented for ultraviolet photodetectors (UV PD).

Synthesis and characterization of water-soluble ZnO quantum dots prepared through PEG-siloxane coating

2008 ◽  
Vol 32 (8) ◽  
pp. 1388 ◽  
Author(s):  
Ralph-Olivier Moussodia ◽  
Lavinia Balan ◽  
Raphaël Schneider
Keyword(s):  
Quantum Dots ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Zno Quantum Dots

Luminescence Properties of Sm3+/Eu3+ Co-Doped ZnO Quantum Dots

2016 ◽  
Vol 16 (4) ◽  
pp. 3597-3601
Author(s):  
Fengyi Liu ◽  
Hong Li ◽  
Yajing Hu ◽  
Na Jin ◽  
Yun Mou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Sol Gel ◽  
Spherical Shape ◽  
Hexagonal Wurtzite Structure ◽  
Luminescence Properties ◽  
Transmission Electron ◽  
Doped Zno ◽  
Zno Quantum Dots ◽  
Zno Qds ◽  
Co Doped

In order to improve luminescence properties of semiconductor ZnO quantum dots (QDs), Sm3+/Eu3+ co-doped ZnO QDs have been controllably synthesized by sol–gel method in this paper. ZnO QDs have a spherical shape with mean diameter at about 5–6 nm, which was characterized by high-resolution transmission electron microscopy (HRTEM). ZnO QDs have hexagonal wurtzite structure with parts of Sm3+ and Eu3+ incorporated into the lattice, which was demonstrated by X-ray Diffraction (XRD). Luminescence properties at room temperature (RT) of different amount of Sm3+ and 2 mol% Eu3+ doped ZnO QDs were examined in-depth by optical spectra. In contrast to the Pr3+/Eu3+ co-doped fluorescent performance researched in our previous study, the photoluminescence (PL) spectra indicates the unique luminescence properties of Sm3+/Eu3+ co-doped ZnO QDs. In addition, fluorescence lifetimes were obtained to illustrate the luminous mechanism.

Microstructure and Luminescence Properties of Tb3+ Doped ZnO Quantum Dots

2016 ◽  
Vol 16 (4) ◽  
pp. 3592-3596 ◽  
Author(s):  
Na Jin ◽  
Hong Li ◽  
Fengyi Liu ◽  
Ya-Hong Xie
Keyword(s):  
Quantum Dots ◽  
Surface Defects ◽  
Light Emission ◽  
Sol Gel ◽  
Spherical Shape ◽  
Hexagonal Wurtzite Structure ◽  
Quenching Effect ◽  
Doped Zno ◽  
Zno Quantum Dots ◽  
Zno Qds

In order to increase the exchange efficiency of solar cells by down-conversion, Tb3+ doped ZnO quantum dots (QDs) were successfully synthesized by sol–gel process. The X-ray diffraction (XRD) results indicate that ZnO QDs have hexagonal wurtzite structure. ZnO QDs have a spherical shape and diameter around 5 nm, which was confirmed by high-resolution transmission electron microscopy (HRTEM). The intensity of visible light emission peaks becomes strengthened and then weakened with the increase of Tb3+ doping concentration. When the concentration is more than 1%, because of the decrease of surface defects and concentration quenching effect, the emissive intensity is weakened. The enhancement of the PL emission peaks at 542 nm, 582 nm, and 619 nm was assigned to energy transfer between Tb3+ ions and ZnO QDs host. Moreover, the absorption spectra also demonstrates energy transfers from Tb3+ ions to ZnO QDs.

scholarly journals The Effects of Zinc Oxide (ZnO) Quantum Dots (QDs) Embedment on the Physicochemical Properties and Photocatalytic Activity of Titanium Dioxide (TiO2) Nanoparticles

2021 ◽  
Vol 32 (2) ◽  
pp. 71-85
Author(s):  
Anwar Iqbal ◽  
Usman Saidu ◽  
Farook Adam ◽  
Srimala Sreekantan ◽  
Normawati Jasni ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Zinc Oxide ◽  
Titanium Dioxide ◽  
Physicochemical Properties ◽  
Quantum Confinement Effect ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Fluorescent Light ◽  
Zno Quantum Dots ◽  
Zno Qds

In this study, a detailed investigation on the effect of zinc oxide (ZnO) quantum dots (QDs) embedment on the physicochemical properties of anatase titanium dioxide (TiO2) was conducted. The highly porous nanocomposite labelled as ZQT was prepared via the sol-gel assisted hydrothermal method. The powder X-ray diffraction (XRD) analysis indicates that the average crystallite size of the ZnO QDs, anatase TiO2 (TiO2 NPs) and ZQT were 4.45 nm, 9.22 nm and 11.38 nm, respectively. Photoluminescent (PL) analysis detected the presence of defects related to TiO2, oxygen vacancies and quantum confinement effect (QCE) of the ZnO QDs in ZQT. These features enhanced the photodegradation of tetracycline (TC) under 48 watt of fluorescent light irradiation when ZQT (98.0%) was used compared to TiO2NPs (32.4%) and ZnO QDs (68.8%). The photodegradation activity was driven by O2●− followed by ●OH and h+.

scholarly journals In Situ Preparation of Amphibious ZnO Quantum Dots with Blue Fluorescence Based on Hyperbranched Polymers and their Application in Bio-Imaging

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 144 ◽  
Author(s):  
Gaiying Lei ◽  
Shu Yang ◽  
Ranran Cao ◽  
Peng Zhou ◽  
Han Peng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Gene Transfection ◽  
Heating Time ◽  
Water Soluble ◽  
Molar Ratio ◽  
Quantum Yields ◽  
Blue Fluorescence ◽  
In Situ Preparation ◽  
Bio Imaging ◽  
Zno Quantum Dots

A new strategy for preparing amphibious ZnO quantum dots (QDs) with blue fluorescence within hyper-branched poly(ethylenimine)s (HPEI) was proposed in this paper. By changing [Zn2+]/[OH−] molar ratio and heating time, ZnO QDs with a quantum yields (QY) of 30% in ethanol were obtained. Benefiting from the amphibious property of HPEI, the ZnO/HPEI nanocomposites in ethanol could be dissolved in chloroform and water, acquiring a QY of 53%, chloroform and 11% in water. By this strategy, the ZnO/HPEI nano-composites could be applied in not only in optoelectronics, but also biomedical fields (such as bio-imaging and gene transfection). The bio-imaging application of water-soluble ZnO/HPEI nanocomposites was investigated and it was found that they could easily be endocytosed by the COS-7 cells, without transfection reagent, and they exhibited excellent biological imaging behavior.

Defect-rich ZnO quantum dots as a potential multifunctional sunscreen and cosmetic active ingredient

2015 ◽  
Vol 87 (9-10) ◽  
pp. 971-977 ◽  
Author(s):  
Adersh Asok ◽  
Ajit R. Kulkarni ◽  
Mayuri N. Gandhi
Keyword(s):  
Quantum Dots ◽  
Active Ingredient ◽  
Visible Region ◽  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Zno Nps ◽  
Visible Luminescence ◽  
Zno Quantum Dots ◽  
Zno Qds

AbstractIn sunscreens, ZnO nanoparticles (NPs) are used as inorganic UV filter which have a prominent band edge emission in the UVA region (~385 nm). When applied to biological surface, this highly penetrating UVA emission from ZnO NPs would enhance the generation of reactive oxygen species resulting in oxidative stress. Therefore, the elimination of this harmful UVA emission from ZnO NPs are much sought after for the development of safer sunscreens. In this paper we introduce the use of defect-rich ZnO (D-ZnO) quantum dots (QDs) as a multifunctional active ingredient in sunscreen/cosmetic application. These D-ZnO QDs make use of their defect energy levels to emit in visible region by bypassing their harmful band edge emission at UVA region. The D-ZnO QDs also showed prominent visible luminescence which matches well with the autofluorescence of in vivo human skin. Hence, this visible luminescence could be useful for camouflaging, thereby enabling its potential as a biologically safe active ingredient for both cosmetic and UV screening applications.

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