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 ◽  
...  

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.

2008 ◽  
Vol 32 (8) ◽  
pp. 1388 ◽  
Author(s):  
Ralph-Olivier Moussodia ◽  
Lavinia Balan ◽  
Raphaël Schneider

NANO ◽  
2016 ◽  
Vol 11 (07) ◽  
pp. 1650073 ◽  
Author(s):  
Lu Liu ◽  
Hu Xu ◽  
Bing Shen ◽  
Xinhua Zhong

Pentaerythritol tetrakis 3-mercaptopropionate (PTMP) grafted poly(acryl acid) (PAA) ionic hydrophilic oligomer PAA-PTMP (PP) and dihydrolipoic acid (DHLA) grafted methoxypoly(ethylene glycol) (mPEG) nonionic hydrophilic oligomer mPEG-DHLA (PD) have been designed, synthesized and used as co-capping ligands in water-solubilization of hydrophobic quantum dots (QDs) via ligand exchange. The obtained oligomers with multi-thiol groups could bind strongly to the surface atoms of QDs. Meanwhile, the carboxyl groups (from PP) and mPEG segment (from PD) can render QDs water-soluble, and the free carboxylic groups can possibly be used for the further bioconjugation. The resulting water-soluble QDs have been characterized by ultraviolet-visible (UV-Vis), fluorescence, Fourier transform infrared (FTIR) spectroscopy as well as transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques. The water-soluble QDs have relatively small hydrodynamic size (10[Formula: see text]12 nm), and importantly, retain high fluorescence quantum yields (up to 45%) compared with that of the originally hydrophobic QDs (49%). In addition, they have tunable surface charges and show excellent colloidal stability over a relatively broad pH range ([Formula: see text]), in high salt concentration, and even after thermal treatment at 100[Formula: see text]C. These results indicate that the water-soluble QDs coated by PP and PD oligomers have potential applications in cellular imaging and biosensor.


2010 ◽  
Vol 663-665 ◽  
pp. 96-99
Author(s):  
Heng Kang Qiu ◽  
Yue Shen ◽  
Lin Jun Wang ◽  
Jian Cheng Zhang ◽  
Kai Feng Qin

High performance aqueous CdSe quantum dots (QDs) have been prepared by combination of Se source as vapor-phase and hydrothermal method. The main advantages of this approach included: one is to utilize H2Se vapor as a higher pure selenium source to make the prepared QDs have little other impurities, another is to obtain the QDs with characteristics of more rapid growth in the hydrothermal reaction. The as-prepared products have been characterized by ultraviolet-visible absorption spectra, photoluminescence spectroscopy (PL), X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and energy dispersive spectroscopy (EDS) analysis etc. The results show the as-synthesized water-soluble CdSe nanoparticles possess higher purity and quantum yields (QY), favorable narrow photoluminescence band with full width of half-maximum (FWHM) down to 40 nm, better photo-stability, and less synthetic time as compared with aqueous CdSe QDs obtained by other methods.


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

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


2011 ◽  
Vol 306-307 ◽  
pp. 1350-1353 ◽  
Author(s):  
Juan Juan Lu ◽  
Shen Guang Ge ◽  
Fu Wei Wan ◽  
Jing Hua Yu

This paper describes the synthesis of CdTe and CdTe/CdS core-shell quantum dots (QDs) in aqueous solution. The quantum dots are prepared by using thioglycolic acid (TGA) as stabilizers. The synthesis procedure is simple and controllable. Different sized CdTe QDs with tuned PL wavelengths from 550 to 640 nm was synthesized by controlling reaction time within 5 h in aqueous solutions at a temperature of 100 °C. We also investigated the influence of precursor Cd/Te molar ratio for the prepared QDs. It was showed that the core-shell CdTe/CdS QDs have larger photoluminescence (PL) emission intensity than the original CdTe QDs. The synthesized core-shell CdTe/ZnS QDs have high quality, water-soluble and will be useful in applications of biolabeling, biosensing, and imaging.


2018 ◽  
Vol 71 (7) ◽  
pp. 524 ◽  
Author(s):  
Rongfang Wang ◽  
Xingming Wei ◽  
Jun Xie ◽  
Bomei Wang ◽  
Xiaotong He

Hydrazine hydrate was used as a novel reducing agent for the synthesis of water soluble and stable cadmium selenide (CdSe) quantum dots (QDs). The as-prepared CdSe quantum dots were investigated by X-ray powder diffraction, high-resolution transmission electron microscopy, photoluminescence, and UV-vis absorption spectroscopy analyses. The results show that the as-prepared CdSe QDs possess a cubic crystal structure and an average size of 2 nm. The effects of the pH of the original solution, thioglycollic acid (TGA)/Cd2+ molar ratio (nTGA/nCd2+), and the Cd/Se molar ratio on the luminescence properties of CdSe QDs were also systematically analysed.


2011 ◽  
Vol 365 ◽  
pp. 18-22
Author(s):  
Jun Lin Wen ◽  
Dai Gui He ◽  
Su Qing Zhao

Influenza is a common acute viral disease that has caused massive harm to human, so a rapid pathogen-detecting method is required for monitoring the status of the disease. Quantum dots are promising emerging fluorescent probe for diagnostic assay. In this work, water soluble ZnO quantum dots were covalently conjugated to rabbit anti-chicken IgY antibody to prepare the quantum dots-linked secondary antibody. The conjugate was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorescence spectrophotometer. Fluorescent quantum dots-based immunosorbent assay was conducted to determine the concentration of influenza B virus. We found that rabbit anti-chicken IgY antibody augmented its molecular weight while coupled to ZnO quantum dots, but the emission spectrum didn’t change. More importantly, the luminescence intensity of QDs correlated to viral concentration in a linear relationship. These results may suggest a potential new approach for quantifying virus, pathogenic bacteria and toxic molecule.


2007 ◽  
Vol 18 (21) ◽  
pp. 215604 ◽  
Author(s):  
Y L Wu ◽  
C S Lim ◽  
S Fu ◽  
A I Y Tok ◽  
H M Lau ◽  
...  

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