scholarly journals Synthesis of Gold Nanoparticles Using p-Aminobenzoic Acid and p-Aminosalicylic Acid as Reducing Agent

2019 ◽  
Vol 19 (1) ◽  
pp. 68
Author(s):  
Abdul Aji ◽  
Eko Sri Kunarti ◽  
Sri Juari Santosa

Synthesis of gold nanoparticles (AuNPs) by reduction of HAuCl4 with p-aminobenzoic acid and p-aminosalicylic acid as a reducing agent was investigated. This work was conducted in order to determine the optimum condition of AuNPs synthesis and examine the effect of the hydroxyl group in p-aminosalicylic acid towards the size, shape, and stability of the synthesized gold nanoparticles (AuNPs). The optimum condition of the gold nanoparticles synthesis was determined by UV/Vis spectrophotometer, the shape and size of gold nanoparticles were measured by Transmission Electron Microscope (TEM). The synthesis process was started by reacting HAuCl4 and the reducing agents in an aqueous solution at 86 ºC. The initial gold concentration, reducing agents concentration and pH were varied in order to obtain the optimum condition. In the optimum condition, the results showed that p-aminosalicylic acid containing both hydroxyl and amino groups performed higher reduction ability compared to p-aminobenzoic acid that only containing an amino group. Reducing agents which have a hydroxyl group (p-aminosalicylic acid) could produce AuNPs with a smaller concentration of HAuCl4 than p-aminobenzoic acid. Gold nanoparticles that were synthesized with p-aminosalicylic acid were more stable and had a smaller particle size compared to its counterpart that is synthesized with p-aminobenzoic acid.

2020 ◽  
Vol 20 (2) ◽  
pp. 413
Author(s):  
Abdul Aji ◽  
Sri Juari Santosa ◽  
Eko Sri Kunarti

In this work, we determined the influenced of the reaction time at the synthesis of gold nanoparticles (AuNPs) by p-aminosalicylic acid and p-aminobenzoic acid as reducing agent. Besides working as a reducing agent, the p-aminobenzoic acid and p-aminosalicylic acid also simultaneously played a role as a capping agent/stabilizing agent. Gold ion was first mixed with the pH adjusted p-aminobenzoic acid and p-aminosalicylic acid. The mixture then heated in boiling water at 86 °C. The formation of AuNPs was indicated by the appearance of red color and analyzed with UV/Vis spectrophotometry to evaluate their surface plasmon resonance (SPR) absorption in the wavelength range 400–800 nm. The reducing ability of the reducing agents was affected by its structure. Gold nanoparticles that were synthesized with p-aminosalicylic acid were more stable, faster and had a smaller size than its counterpart that is synthesized with p-aminobenzoic acid. The stability test over a periods 5 months showed that AuNPs were relatively stable.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2937
Author(s):  
Muhammad Zulfajri ◽  
Wei-Jie Huang ◽  
Genin-Gary Huang ◽  
Hui-Fen Chen

The laser ablation synthesis in solution (LASiS) method has been widely utilized due to its significant prospects in laser microprocessing of nanomaterials. In this study, the LASiS method with the addition of different surfactant charges (cationic CTAB, nonionic TX-100, and anionic SDS) was used to produce Au NPs. An Nd:YAG laser system at 532 nm excitation with some synthetic parameters, including different laser fluences, ablation times, and surfactant concentrations was performed. The obtained Au NPs were characterized by UV-Vis spectroscopy, transmission electron microscopy, and zeta potential analyzer. The Au NPs exhibited the maximum absorption peak at around 520 nm for all samples. The color of Au NPs was changed from red to reddish by increasing the laser fluence. The surfactant charges also played different roles in the Au NPs’ growth during the synthesis process. The average sizes of Au NPs were found to be 8.5 nm, 5.5 nm, and 15.5 nm with the medium containing CTAB, TX-100, and SDS, respectively. Besides, the different surfactant charges induced different performances to protect Au NPs from agglomeration. Overall, the SDS and CTAB surfactants exhibited higher stability of the Au NPs compared to the Au NPs with TX-100 surfactant.


2007 ◽  
Vol 121-123 ◽  
pp. 251-254 ◽  
Author(s):  
Zhi Rui Guo ◽  
Y. DuanMu ◽  
Ning Gu

Nanoscaled fibrous aggregates of gold nanoparticles have been synthesized by a simultaneous reduction-oxidation polymerization process using aniline as reducing agent as well as monomer in an ethanol medium. Time-dependent UV-Vis absorption spectroscopy was used to track the formation process of gold nanoparticles. The transmission electron microscopy (TEM) images and Fourier transform infrared (FT-IR) spectrum of the as-preapred products indicate these gold nanoparticles were binded by the oxidation polymerization resultant of aniline.


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Shohreh Hemmati ◽  
Erin Retzlaff-Roberts ◽  
Corren Scott ◽  
Michael T. Harris

An environmentally friendly technique has been developed to produce metal nanoparticles using green synthesis methods. In this study, silver nanostructures were synthesized using different sugar substitutes and artificial sweeteners as green reducing agents in an aqueous solution at low temperature. The main ingredients (such as maltodextrin, sucrose, saccharin, and sucralose) of the artificial sweeteners acting as reducing agents were used to reduce Ag+ ions to Ag0. The pH of the solution was controlled during synthesis through the addition of sodium hydroxide (NaOH) to increase the strength of the reducing agents by converting nonreducing sugars to reducing ones and consequently increasing the rate of silver nanoparticle formation. The size and morphology of the synthesized nanostructures were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The formation of nanostructures during the course of the reactions was investigated by UV-visible (UV-vis) spectroscopy characterization of an aliquot of sample at specific intervals. The function of each artificial sweetener and corresponding ingredients as a reducing agent and capping agent was investigated by Fourier-transform infrared spectroscopy (FTIR) and mass spectrometry (MS).


2017 ◽  
Vol 901 ◽  
pp. 26-31 ◽  
Author(s):  
Dian Susanthy ◽  
Fadliah ◽  
Endang Tri Wahyuni ◽  
Sri Juari Santosa

Synthesis of silver nanoparticles (AgNPs) by reduction of AgNO3 with o-hydroxybenzoic, p-hydroxybenzoic and o,p-dihydroxybenzoic acids as reducing agents was investigated. This research was conducted to determine the effect of the position and number of hydroxyl groups towards the size, shape and stability of the resulted AgNPs. Surface Plasmon Resonance (SPR) of AgNPs was characterized by UV/Vis spectrophotometer, the shape and size of AgNPs was determined by Transmission Electron Microscope (TEM). The results showed that the reducing agent that has substituents in the para position (p-hydroxybenzoic acid) has the higher reduction ability than the others. AgNPs were yielded by all types of reducing agents in alkaline system. Reducing agents which have greater number of substituents (o,p-dihydroxybenzoic acid) could produce AgNPs with smaller concentration of AgNO3 than the others. AgNPs that was produced by reducing agent having substituents on the para position (p-hydroxybenzoic acid) was more stable and smaller particle size, i.e. 34 ± 1.78 nm than reducing agent that has substituent on the ortho para positions (with particle size 45 + 3.67 nm) and ortho positions (with particle size 70 ± 4.96 nm).


2015 ◽  
Vol 10 (4) ◽  
pp. 1934578X1501000
Author(s):  
Yu Seon Seo ◽  
Song-Hyun Cha ◽  
Seonho Cho ◽  
Hye-Ran Yoon ◽  
Young-Hwa Kang ◽  
...  

The sustainable synthesis of gold nanoparticles from gold ions was conducted with caffeic acid as a green reducing agent. The formation of gold nanoparticles was confirmed by spectroscopic and microscopic methods. Spherical nanoparticles with an average diameter of 29.99 ± 7.43 nm were observed in high-resolution transmission electron microscopy and atomic force microscopy images. The newly prepared gold nanoparticles exhibited catalytic activity toward the reduction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride. This system enables the preparation of green catalysts using plant natural products as reducing agents, which fulfills the growing need for sustainability initiatives.


2018 ◽  
Vol 19 (2) ◽  
pp. 72
Author(s):  
Iwan Syahjoko Saputra ◽  
Yoki Yulizar ◽  
Sudirman Sudirman

Gold Nanoparticles (GoldNPs) successful was performed using HAuCl4 precursor as Au3+ ion source with 7x10-4 M concentration. The research aims to knows effect of concentration variation of Imperata cylindrica L leaf extract on synthesis process of gold nanoparticles. The research used of green synthesis method. Colloid of nanoparticles which is formed in analyzed using UV-Vis Spectrophotometer, FT-IR Spectroscopy, PSA, PZC, XRD and TEM. The results of synthesis showed the best concentration of Imperata cilindrica L leaf extract at 3,46%, happen a shift of wavelength at UV-Vis from 216 nm to 530 nm with 1.779 absorbance value. The PSA analysis showed a particle size of 51.87 nm and a PZC value of -19.2 mV. The result of FT-IR indicated a shift of wavenumber in the hidroxyl group from 3354 cm-1 to 3390 cm-1 and showed a interaction of hydroxyl group at imperata cylindrica L leaf extract with Au3+ ion. TEM analysis shows the morphology of GoldNPs that spherical shape with a particle size of 20 nm. XRD calculation results show crystallite size of gold nanoparticles is 15.47 nm.


NANO ◽  
2014 ◽  
Vol 09 (08) ◽  
pp. 1450085
Author(s):  
PENG LI ◽  
HOUSHENG XIA ◽  
GUISHENG YANG

A precipitation–reduction synthesis method for silver nanoparticles ( Ag NPs) was developed. Molten ε-caprolactam (CL) was used not only as solvent but also as reducing agent and stabilizer. At first, Ag 2 O NPs was prepared by precipitation reaction of silver nitrate ( AgNO 3) and sodium hydroxide ( NaOH ) using molten CL as solvent at 100°C. Then, Ag 2 O NPs was in situ reduced into Ag NPs by molten CL at 120°C. Techniques of X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to monitor the synthesis process. With the increase of reduction time, monodispersed Ag 2 O NPs (ca. 3.7 nm) were integrated and larger Ag NPs (10–90 nm) were formed. Fourier transform infrared (FT-IR) results showed that the surface of Ag NPs was capped with about 0.9 wt.% of CL molecules. Surface enhanced Raman scattering (SERS) effect of Ag NPs was investigated using Rhodamine 6G as a probe molecule.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Min Song ◽  
Juan Xu ◽  
Changzi Wu

In our study, graphene oxide is synthesized by Hummers method. And then, carboxylic acid functionalized graphene (graphene-COOH), thiol-functionalized graphene (graphene-SH), and highly dispersive graphene are prepared by chemical modification of respective groups on the graphene surface. Furthermore, we explore a solution-based approach to prepare three differently functionalized graphene-gold composites by one-step chemical reduction ofAuCl4 -ions in respective functionalized graphene suspensions, where the gold nanoparticles are deposited on the functionalized graphene surface during their synthesis process. In addition, we compare the influence of surface functionalization on the growth of gold nanoparticles on graphene surface. Transmission electron morphology (TEM) and ultraviolet-visible (UV-Vis) spectroscopy are employed to study the effect of surface functionalities on AuNPs distribution onto the graphene surface and demonstrate the successful immobilization of AuNPs on graphene surface.


Respuestas ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 49-55
Author(s):  
Francisco Javier Flórez Barajas ◽  
Zayda Constanza Sánchez Acevedo ◽  
Heriberto Peña Pedraza

Currently the metallic nanoparticles, in particular of noble metals like gold are gaining importance due to their potential applications in various fields, as their physicochemical properties and their low toxicity the materials become of great importance. In this paper the synthesis of gold nanoparticles was carried out in solution using a reducing agent as is the biomolecule chitosan as reducing agent and were also characterized by a spectrophotometric technique as ultraviolet visible to verify the efficiency of the synthesis process, the spectrum showed that the synthesized nanoparticles have an absorption band at 525 nm. characteristic of gold particles to nanometric size.


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