scholarly journals An imine-based approach to prepare amine-functionalized Janus gold nanoparticles

2015 ◽  
Vol 51 (58) ◽  
pp. 11622-11625 ◽  
Author(s):  
Shaojue Wu ◽  
Si Yu Tan ◽  
Chung Yen Ang ◽  
Kim Truc Nguyen ◽  
Menghuan Li ◽  
...  

An imine-based approach was developed to prepare Janus gold nanoparticles having amine functionality on one patch of the surface and a polyethylene glycol unit on the other.

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
M. Tajdidzadeh ◽  
A. B. Zakaria ◽  
Z. Abidin Talib ◽  
A. S. Gene ◽  
S. Shirzadi

In the present study, gold nanoparticles were synthesized in various polymer solutions by means of employing laser ablation technique at the same ablation time. Specifically, gold nanoparticles were synthesized in polyethylene glycol and chitosan solutions, in order to compare the effects of the liquid media which served as stabilizers for particle size and volume fraction of nanoparticles. In addition, this experiment was repeated in distilled water for reference purposes. As the findings indicated, the particle size which was obtained in polyethylene glycol was about 7.49 nm, that is, smaller than those of chitosan solution and distilled water, respectively. In contrast, it was observed that the volume fraction of gold nanoparticles increased in polyethylene glycol in comparison with the other media which indicated an effect on the formation of NPs. On the other hand,Z-scan technique was employed to measure the nonlinear refractive index and nonlinear absorption coefficient of nanofluids containing gold nanoparticles. Consequently, the nonlinear properties of nanofluids pointed to a significant contribution with the number of nanoparticles observed in fluids and both optical nonlinear parameters were observed to increase by means of a prior increase in the volume fraction of Au-NPs in polyethylene glycol solution.


2015 ◽  
Vol 1108 ◽  
pp. 15-20 ◽  
Author(s):  
Bashiru Kayode Sodipo ◽  
Azlan Abdul Aziz

The UV and IR block properties of superparamagnetic magnetite nanoparticles (SPMN) and SPMN/gold composite nanoparticles are investigated. The composite nanoparticles were prepared via sonochemical assisted reduction of gold precursor and deposition of gold nanoparticles (GNP) on amine functionalized SPMN. Protective properties of the SPMN and the composite nanoparticles were demonstrated via spectrophotometer measurements. Unlike in the visible and infrared region, there was 0% transmission of radiation through bare SPMN in the UV region. The presence GNP in the composites nanoparticles affects the protecting properties of the SPMN with almost 40% transmission in the UV region. The SPMN/GNP composite nanoparticles were able to block some radiation in the visible region. On the other hand, there was nearly uniform 90% and continuous transmission of infrared rays in naked SPMN and SPMN/GNP composite nanoparticles, respectively.


MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3353-3360
Author(s):  
Susana Helena Arellano Ramírez ◽  
Perla García Casillas ◽  
Christian Chapa González

AbstractA significant area of research is biomedical applications of nanoparticles which involves efforts to control the physicochemical properties through simple and scalable processes. Gold nanoparticles have received considerable attention due to their unique properties that they exhibit based on their morphology. Gold nanospheres (AuNSs) and nanorods (AuNRs) were prepared with a seed-mediated method followed of polyethylene glycol (PEG)-coating. The seeds were prepared with 0.1 M cetyltrimethyl-ammonium bromide (CTAB), 0.005 M chloroauric acid (HAuCl4), and 0.01 M sodium borohydride (NaBH4) solution. Gold nanoparticles with spherical morphology was achieved by growth by aggregation at room temperature, while to achieve the rod morphology 0.1 M silver nitrate (AgNO3) and 0.1 M ascorbic acid solution were added. The gold nanoparticles obtained by the seed-mediated synthesis have spherical or rod shapes, depending on the experimental conditions, and a uniform particle size. Surface functionalization was developed using polyethylene glycol. Morphology, and size distribution of AuNPs were evaluated by Field Emission Scanning Electron Microscopy. The average size of AuNSs, and AuNRs was 7.85nm and 7.96 x 31.47nm respectively. Fourier transform infrared spectrometry was performed to corroborate the presence of PEG in the AuNPs surface. Additionally, suspensions of AuNSs and AuNRs were evaluated by UV-Vis spectroscopy. Gold nanoparticles were stored for several days at room temperature and it was observed that the colloidal stability increased once gold nanoparticles were coated with PEG due to the shield formed in the surface of the NPs and the increase in size which were 9.65±1.90 nm of diameter for AuNSs and for AuNRs were 29.03±5.88 and 8.39±1.02 nm for length and transverse axis, respectively.


1976 ◽  
Vol 64 (2) ◽  
pp. 369-378 ◽  
Author(s):  
K. W. Beyenbach ◽  
L. B. Kirschner

1. The assumption that (3H) methoxy inulin, (14C) polyethylene glycol (PEG) and (125) iothalamate (glofil) are reliable volume and glomerular markers in teleosts was tested. 2. PEG occupied smaller volumes than inulin and glofil in sea-water-adapted Salmo gairdneri. Ureteral clearances of PEG were about 22% higher than those of inulin and glofil, and urine-to-plasma ratios were significantly greater for PEG than for the other two markers. 3. After introduction into the urinary bladder the three macro-molecules appeared in the plasma, PEG at the lowest rates. 4. These observations indicate that mammalian glomerular markers can penetrate the bladder and possibly the ureters and renal tubules. Therefore, their clearances may not give a true measure of glomerular filtration rates in teleosts.


2016 ◽  
Vol 28 (1) ◽  
pp. 239-243 ◽  
Author(s):  
Shuaidong Huo ◽  
Shizhu Chen ◽  
Ningqiang Gong ◽  
Juan Liu ◽  
Xianlei Li ◽  
...  

2011 ◽  
Vol 115 (8) ◽  
pp. 3279-3285 ◽  
Author(s):  
Yoshikiyo Hatakeyama ◽  
Takeshi Morita ◽  
Satoshi Takahashi ◽  
Kei Onishi ◽  
Keiko Nishikawa

Author(s):  
RADITYA ISWANDANA ◽  
RICHA NURSELVIANA ◽  
SUTRIYO SUTRIYO

Objective: Gold nanoparticles (AuNPs) are highly useful for drug delivery, but their application is limited by their stability as they readily aggregate.This issue can be prevented by adding a stabilizing agent such as resveratrol (RSV), which is a polyphenol derived from plants, that is used to preventcancer. Therefore, we propose a novel method to prepare stable RSV-conjugated nanoparticles modified with polyethylene glycol (RSV-AuNP-PEG).Methods: In the first step, the Turkevich method was used to synthesize the AuNPs. Then, PEG was added as stabilizer agent and conjugated with RSV.The synthesized conjugates were characterized using ultraviolet-visible spectrophotometry, Fourier transform infrared spectroscopy, particle sizeanalysis, and high-performance liquid chromatography.Results: The obtained RSV-AuNP-PEG had a particle size of 83.93 nm with a polydispersity index (PDI) of 0.562 and formed a translucent purple-redfluid in solution. The zeta potential was −22.9 mV, and the highest entrapment efficiency was 75.86±0.66%. For comparison, the RSV-AuNP solutionwas purple and turbid, the particle size was 51.97 nm with a PDI of 0.694, and the zeta potential was −24.6 mV. The stability test results showed thatthe storage stability of RSV-AuNP-PEG was better than that of AuNP-RSV. Further, the RSV-AuNP-PEG was shown to be most stable in 2% bovine serumalbumin (BSA) while the AuNP-RSV was most stable in 2% BSA in phosphate-buffered saline pH 7.4.Conclusion: These results show that modification of RSV-conjugated AuNPs with PEG effectively prevents their aggregation in storage, but only incertain mediums.


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