Water-based synthesis of gold and silver nanoparticles with cuboidal and spherical shapes using luteolin tetraphosphate at room temperature

2018 ◽  
Vol 5 (4) ◽  
pp. 917-932 ◽  
Author(s):  
Francis J. Osonga ◽  
Phuong Le ◽  
David Luther ◽  
Laura Sakhaee ◽  
Omowunmi A. Sadik

The demand for eco-friendly synthetic methods of metal nanoparticles is on the rise.

2009 ◽  
Vol 6 (5/6) ◽  
pp. 541 ◽  
Author(s):  
Akanksha Singh ◽  
Mandar Shirolkar ◽  
Niranjan Prasad Lalla ◽  
Chantal Khan Malek ◽  
S.K. Kulkarni

RSC Advances ◽  
2021 ◽  
Vol 11 (24) ◽  
pp. 14624-14631
Author(s):  
Pablo Eduardo Cardoso-Avila ◽  
Rita Patakfalvi ◽  
Carlos Rodríguez-Pedroza ◽  
Xochitl Aparicio-Fernández ◽  
Sofía Loza-Cornejo ◽  
...  

Gold and silver nanoparticles were synthesized at room temperature using an aqueous extract from dried rosehips acting as reducing and capping agents with no other chemicals involved.


2020 ◽  
Vol 4 (2) ◽  

Metal nanoparticles possess an extensive scientific and technological significance due to their unique physiochemical properties and their potential applications in different fields like medicine. Silver and gold nanoparticles have shown to have antibacterial and cytotoxic activities. Conventional methods used in the synthesis of the metal nanoparticles involve use of toxic chemicals making them unsuitable for use in medical field. In our continued effort to explore for simple and eco-friendly methods to synthesize the metal nanoparticles, we here describe synthesis and characterization of gold and silver nanoparticles using Gonaderma lucidum, wild non-edible medicinal mushroom. G. lucidum mushroom contain bioactive compounds which can be involved in the reduction, capping and stabilization of the nanoparticles. Antibacterial activity analysis was done on E. coli and S. aureus. The synthesis was done on ultrasonic bath. Characterization of the metal nanoparticles was done by UV-VIS., High Resolution Transmission Electron Microscope (HRTEM) and FTIR. HRTEM analysis showed that both silver and gold nanoparticles were spherical in shape with an average size of 15.82±3.69 nm for silver and 24.73±5.124nm for gold nanoparticles (AuNPs). FTIR analysis showed OH and -C=C- stretching vibrations, an indication of presence of functional groups of biomolecules capping both gold and silver nanoparticles. AgNPs showed inhibition zones of 15.5±0.09mm and 13.3±0.14mm while AuNPs had inhibition zones of 14.510±0.35 and 13.3±0.50mm on E. coli and S. aureus respectively. The findings indicate the potential use of AgNPs and AuNPs in development of drugs in management of pathogenic bacteria.


Author(s):  
Mohammad Tariq Yaseen

Metal nanoparticles are very important for their optical properties when they interact with light. Metal nanoparticles have the ability to confine the collective oscillation of electrons, which is called localized surface plasmon resonance (LSPR). In this work, silver nanoparticles have been proposed to enhance light harvesting, which could be useful for different applications. Metal nanoparticles such as gold and silver nanoparticles have the ability to concentrate field in a very small space. In this study, gold and silver nanoparticles optical response was investigated using frequency domain simulation. The resonance wavelength of gold and silver nanoparticles was about 550 nm and 400 nm, respectively. Silver nanoparticles showed better LSPR performance than gold nanoparticles. Therefore, silver nanoparticles were chosen for optical field enhancement. Here silver nanoparticles were placed on a silicon substrate for optical field enhancement. To study the effect of size on the optical response of silver nanoparticles, the optical properties of this structure with different silver nanoparticles diameter values were investigated. Silver nanoparticles with 40 nm diameters showed a better optical response. To study the effect of the distance between silver nanoparticles on the optical response, different gap values were put between silver nanoparticles. The gap value of 4 nm showed a better optical response. The obtained results showed that the localized field is strongly dependent on the metal type, size, and space between nanoparticles. In addition, the optical field concentration can be controlled by tuning the size and space between silver nanoparticles. This will support localized field enhancement. The enhanced localized field will increase the field absorption near the surface, which can be beneficial for energy harvesting applications such as solar cells and detectors


2020 ◽  
Vol 42 (3) ◽  
pp. 440-440
Author(s):  
Xin Bin Yang Xin Bin Yang ◽  
Chun Mei Wang Chun Mei Wang ◽  
Yu Huang Yu Huang

Gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) were synthesized by using water-soluble Kaempferol–3′–sulfonate acid sodium (KS) alone as the reducing agent. The UV-vis spectra confirmed the formation of the ks-AuNPs and ks-AgNPs which were stable for up to 3 months without any other stabilizing agents at room temperature. The TEM studies exhibited monodispersed and mainly spherical nanoparticles with the size in the range of 15-30 nm and 20-50 nm for ks-AuNPs and ks-AgNPs, respectively. The XRD revealed crystallinity of nanoparticles. The chemical state of Au and Ag on the surface of nanoparticles was analyzed by XPS. The FTIR analysis indicated that the hydroxyl of KS were responsible for the reduction of Au3+ and Ag+ to ks-AuNPs and ks-AgNPs, respectively. Cytotoxic activity of ks-AuNPs and ks-AgNPs on MCF-7 cells is higher than the KS.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Diego Alberto Lomelí-Rosales ◽  
Adalberto Zamudio-Ojeda ◽  
Sara Angélica Cortes-Llamas ◽  
Gilberto Velázquez-Juárez

AbstractNowadays, there are several approaches reported to accomplish the green synthesis of metal nanoparticles by using bacterial and fungi supernatants or by-products generated by these microorganisms. Therefore, agars as solely reductive regents have started to be used in order to obtain metal nanoparticles. This paper shows the results of the synthesis of gold and silver nanoparticles with different morphology, mainly triangular and truncated triangular, using Eosin Methylene Blue (EMB) agar as reducing agent. To control the reaction process, the necessary activation energy for the reducer was provided by three different techniques: microwave radiation, using a domestic microwave oven, ultraviolet radiation, and heating on a conventional plate. The evolution of the reduction process and stability of the samples was performed by ultraviolet visible spectroscopy. Morphology was carefully analyzed using high-resolution transmission electron microscopy (HRTEM) and Transmission electron microscopy (TEM). A one step synthesis for gold and silver nanoparticles was optimized with an eco-friendly and economic process.


2021 ◽  
pp. 89-100 ◽  
Author(s):  
M.A. Osadchuk ◽  
N.V. Kireeva ◽  
N.P. Korzhenkov ◽  
M.V. Trushi

Gold and silver nanoparticles are easily synthesized and the most effective nanostructures in clinical practice. Their optical properties, ease of synthesis, colloidal stability and the ability to form any surface for easier conjugation with biological particles, the ability to individual multiple use, make them especially important in oncology. Gold and silver nanoparticles are capable of providing targeted drug delivery, which depends on the photothermal, photodynamic, and antiangiogenic properties of the metal. Due to their exceptional properties, these nanoparticles are considered as a potential tool for the diagnosis of various types of cancer and drug delivery. The non-toxic and non-immunogenic nature of gold and silver nanoparticles, as well as their high permeability and retention effect, provide additional advantages, allowing drugs to easily penetrate and accumulate at tumor sites. The effectiveness of precious metal nanoparticles as radiosensitizers, dose enhancers and contrast agents is gaining increasing recognition. An important problem associated with the use of biogenic metal nanoparticles is the study of their genotoxicity, since they play an important role in the initiation and progression of abnormalities, including genetic ones.


2019 ◽  
Vol 55 (55) ◽  
pp. 7990-7993 ◽  
Author(s):  
Nathaniel E. Larm ◽  
Dronareddy Madugula ◽  
Mark W. Lee ◽  
Gary A. Baker

Small (<5 nm) gold and silver nanoparticles and their bimetallic counterparts were prepared using the fundamental boron cluster [closo-B10H10]2− as the reducing and stabilizing agent.


2008 ◽  
Vol 8 (7) ◽  
pp. 3565-3569 ◽  
Author(s):  
Sarang S. Puranik ◽  
Hrushikesh M. Joshi ◽  
S. B. Ogale ◽  
K. M. Paknikar

An efficient and facile procedure is developed for concurrent in situ synthesis and ordered assembly of metal nanoparticles on a periodic two dimensional protein array. The S-layer protein of Bacillus subtilis exhibiting uniform pore size is used as template. Synthesis of gold and silver nanoparticles anchoring on the pores of S-layer is achieved by chemical reduction of respective metal salt laden protein template. Transmission electron microscopy reveals formation of well ordered and separated gold and silver nanoparticles with an average diameter of 6 ± 1 nm and 4 ± 1 nm, respectively. The periodic arrangement of nanoparticles is dictated by the native structure of S-layer protein array as the nanoparticle locations are found to be correlated to the nanosized pores of the crystalline S-layer array.


2019 ◽  
Vol 14 ◽  
pp. 155892501986694 ◽  
Author(s):  
Zhanyu Zhang ◽  
Xiaodan Lv ◽  
Qidan Chen ◽  
Jing An

Noble metal nanoparticles and traditional dyes jointly colorate silk fabrics. Gold and silver nanoparticles were in situ synthesized on silk fabrics, and the complex coloration was realized by the integration of traditional dyes into the treated silk. The localized surface plasmon resonance properties of gold and silver nanoparticles were not affected by the coloration of dyed-on silk fabrics. The combined optical properties of nanoparticles and dyes extended the color range and enhanced the color strength (K/S) of silk fabrics. Ultraviolet–visible diffuse absorption spectroscopy and scanning electron microscopy demonstrated the in situ synthesis of gold and silver nanoparticles on silk fabrics. The coloration of traditional dyes influenced the morphologies of gold and silver nanoparticles on fiber surface slightly. The silk fabrics with complex coloration showed significant antibacterial property. The complex coloration based on particular nanoparticles and dyes provides a promising strategy to develop multifunctional textiles.


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