scholarly journals One-Step Synthesis of PEG-Coated Gold Nanoparticles by Rapid Microwave Heating

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Seung Kwon Seol ◽  
Daeho Kim ◽  
Sunshin Jung ◽  
Won Suk Chang ◽  
Ji Tae Kim
Keyword(s):  
Gold Nanoparticles ◽  
Microwave Heating ◽  
Homogeneous Nucleation ◽  
Growth Parameters ◽  
Average Diameter ◽  
Gold Particles ◽  
Initial Stage ◽  
High Uniformity ◽  
One Step ◽  
Primary Gold

Polyethylene Glycol- (PEG-) coated gold nanoparticles (PEG-AuNPs) are synthesized by a one-step route with rapid microwave heating. Homogeneous nucleation of the primary gold particles is enhanced by increasing the applied microwave power during the initial stage of the synthesis, increasing the temperature ramping rate (Rr) and resulting in decreased size and improved uniformity of the synthesized PEG-AuNPs. Using rapid microwave heating, we successfully produce uniform colloidal PEG-AuNPs with an average diameter of14.3±2.5 nm within a few minutes. By appropriate tuning of the growth parameters, microwave synthesis can produce largely colloidal PEG-AuNPs with high uniformity.

scholarly journals Electrochromic Performance and Capacitor Performance of α-MoO3 Nanorods Fabricated by a One-Step Procedure

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 783
Author(s):  
Ying Duan ◽  
Chen Wang ◽  
Jian Hao ◽  
Yang Jiao ◽  
Yanchao Xu ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Average Diameter ◽  
Fast Response ◽  
Cycle Stability ◽  
Electrochromic Devices ◽  
Step Procedure ◽  
One Step ◽  
Supercapacitor Performance ◽  
First Time ◽  
Prepared Nanorods

In this paper, we propose for the first time the synthesis of α-MoO3 nanorods in a one-step procedure at mild temperatures. By changing the growth parameters, the microstructure and controllable morphology of the resulting products can be customized. The average diameter of the as-prepared nanorods is about 200 nm. The electrochromic and capacitance properties of the synthesized products were studied. The results show that the electrochromic properties of α-MoO3 nanorods at 550 nm have 67% high transmission contrast, good cycle stability and fast response time. The MoO3 nanorods also exhibit a stable supercapacitor performance with 98.5% capacitance retention after 10,000 cycles. Although current density varies sequentially, the nanostructure always exhibits a stable capacitor to maintain 100%. These results indicate the as-prepared MoO3 nanorods may be good candidates for applications in electrochromic devices and supercapacitors.

scholarly journals PEGylated Gold Nanoparticles with Interesting Plasmonic Properties Synthesized Using an Original, Rapid, and Easy-to-Implement Procedure

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Ștefan Nițică ◽  
Alin Iulian Moldovan ◽  
Valentin Toma ◽  
Cristian Silviu Moldovan ◽  
Ioana Berindan-Neagoe ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Synthesis Method ◽  
Average Diameter ◽  
Liquid Droplets ◽  
Sers Substrates ◽  
New Class ◽  
One Step ◽  
Short Synthesis ◽  
Spherical Gold Nanoparticles ◽  
Synthesis Procedure

In this letter, we report a new, one-step, rapid, and easy-to-implement method for the synthesis of PEGylated gold nanoparticles (PEG-AuNPs) having a narrow size distribution and very interesting plasmonic properties. Unmodified polyethylene glycol molecules with a molecular weight of 1000 g/mole (PEG1000) have been employed as reducing and capping agents for the synthesis of spherical gold nanoparticles having an average diameter of 35 nm, within a few minutes. The novelty of the herein proposed synthesis method consists in the fact that the synthesis takes place inside of a sealed bottle flask containing aqueous solutions of PEG1000, tetrachloroauric(III) acid (HAuCl4), and NaOH, placed in the center of a microwave oven, capable to provide a very uniform temperature environment. It turned out that, during the very short synthesis procedure (2 minutes), PEG 1000 suffers an oxidative transformation in such a manner that its terminal alcohol groups (-CH2-OH) are transformed in carboxylate ones (-COO−). The as-synthesized PEG-AuNPs possess very interesting plasmonic properties allowing the detection of different molecules by means of SER spectroscopy performed either in liquid droplets or on solid spots. As a consequence of their unique plasmonic properties, the SER spectra acquired using this new class of nanoparticles on different molecules of interest (methylene blue, rhodamine 6G, doxorubicin, and 5-fluorouracil) are highly reproducible, making them ideal candidates for further use as SERS substrates.

scholarly journals One-Step Synthesis of PEGylated Gold Nanoparticles with Tunable Surface Charge

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Rares Stiufiuc ◽  
Cristian Iacovita ◽  
Raul Nicoara ◽  
Gabriela Stiufiuc ◽  
Adrian Florea ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Surface Charge ◽  
Colloidal Stability ◽  
Spherical Shape ◽  
Average Diameter ◽  
Molecular Chain ◽  
Surface Charges ◽  
One Step

The present work reports a rapid, simple and efficient one-step synthesis and detailed characterisation of stable aqueous colloids of gold nanoparticles (AuNPs) coated with unmodified poly(ethylene)glycol (PEG) molecules of different molecular weights and surface charges. By mixing and heating aqueous solutions of PEG with variable molecular chain and gold(III) chloride hydrate (HAuCl4) in the presence of NaOH, we have successfully produced uniform colloidal 5 nm PEG coated AuNPs of spherical shape with tunable surface charge and an average diameter of 30 nm within a few minutes. It has been found out that PEGylated AuNPs provide optical enhancement of the characteristic vibrational bands of PEG molecules attached to the gold surface when they are excited with both visible (532 nm) and NIR (785 nm) laser lines. The surface enhanced Raman scattering (SERS) signal does not depend on the length of the PEG molecular chain enveloping the AuNPs, and the stability of the colloid is not affected by the addition of concentrated salt solution (0.1 M NaCl), thus suggesting their potential use forin vitroandin vivoapplications. Moreover, by gradually changing the chain length of the biopolymer, we were able to control nanoparticles’ surface charge from −28 to −2 mV, without any modification of the Raman enhancement properties and of the colloidal stability.

scholarly journals Facile Green, Room-Temperature Synthesis of Gold Nanoparticles Using Combretum erythrophyllum Leaf Extract: Antibacterial and Cell Viability Studies against Normal and Cancerous Cells

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 893
Author(s):  
Olufunto T. Fanoro ◽  
Sundararajan Parani ◽  
Rodney Maluleke ◽  
Thabang C. Lebepe ◽  
Jose R. Varghese ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Cell Viability ◽  
Leaf Extract ◽  
Room Temperature ◽  
Klebsiella Oxytoca ◽  
Cost Effective ◽  
Average Diameter ◽  
Antibacterial Activities ◽  
Inhibition Concentration ◽  
First Time

We herein report a facile, green, cost-effective, plant-mediated synthesis of gold nanoparticles (AuNPs) for the first time using Combretum erythrophyllum (CE) plant leaves. The synthesis was conducted at room temperature using CE leaf extract serving as a reducing and capping agent. The as-synthesized AuNPs were found to be crystalline, well dispersed, and spherical in shape with an average diameter of 13.20 nm and an excellent stability of over 60 days. The AuNPs showed broad-spectrum antibacterial activities against both pathogenic Gram-positive (Staphylococcus epidermidis (ATCC14990), Staphylococcus aureus (ATCC 25923), Mycobacterium smegmatis (MC 215)) and Gram-negative bacteria (Proteus mirabilis (ATCC 7002), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13822), Klebsiella oxytoca (ATCC 8724)), with a minimum inhibition concentration of 62.5 µg/mL. In addition, the as-synthesized AuNPs were highly stable with exceptional cell viability towards normal cells (BHK- 21) and cancerous cancer cell lines (cervical and lung cancer).

Rapid one-step scalable microwave synthesis of Ti3C2Tx MXene

2021 ◽  
Author(s):  
Jing Zhu ◽  
Jingyi Zhang ◽  
Ruiming Lin ◽  
Benwei Fu ◽  
Chengyi Song ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Microwave Synthesis ◽  
State Of The Art ◽  
Synthesis Time ◽  
One Step

We demonstrate a rapid one-step scalable microwave heating-based method to prepare Ti3C2Tx MXenes, which shortens the synthesis time from tens of hours from state-of-the-art approaches to 15 minutes and avoids...

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