Hydrazine Based Facile Synthesis and Ordered Assembly of Metal Nanoparticles (Au, Ag) on a Bacterial Surface Layer Protein Template

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 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.


2018 ◽  
Vol 271 ◽  
pp. 76-84 ◽  
Author(s):  
Khongorzul Gerelbaatar ◽  
Ariunzaya Tsogoo ◽  
Rentsenmyadag Dashzeveg ◽  
Ninjbadgar Tsedev ◽  
Erdene Ochir Ganbold

In this study, colloidal metal nanoparticles have been prepared by the wet-chemical synthesis method. Gold and silver nanoparticles with approximate sphere shape were synthesized through the citrate-reduction method. The colloidal metal nanoparticles were characterized by using UV-vis absorption spectroscopy, photon cross-correlation spectroscopy (PCCS) and transmission electron microscope (TEM). Catalytic activities of the metal nanoparticles were investigated through reduction of 2,4-dinitrophenol to 2,4-diaminophenol in the presence of NaBH4 at room temperature. Both gold and silver nanoparticles showed an excellent catalytic activity.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2326
Author(s):  
Entesar Ali Ganash ◽  
Reem Mohammad Altuwirqi

In this work, silver nanoparticles (Ag NPs) were synthesized using a chemical reduction approach and a pulsed laser fragmentation in liquid (PLFL) technique, simultaneously. A laser wavelength of 532 nm was focused on the as produced Ag NPs, suspended in an Origanum majorana extract solution, with the aim of controlling their size. The effect of liquid medium concentration and irradiation time on the properties of the fabricated NPs was studied. While the X-ray diffraction (XRD) pattern confirmed the existence of Ag NPs, the UV–Vis spectrophotometry showed a significant absorption peak at about 420 nm, which is attributed to the characteristic surface plasmon resonance (SPR) peak of the obtained Ag NPs. By increasing the irradiation time and the Origanum majora extract concentration, the SPR peak shifted toward a shorter wavelength. This shift indicates a reduction in the NPs’ size. The effect of PLFL on size reduction was clearly revealed from the transmission electron microscopy images. The PLFL technique, depending on experimental parameters, reduced the size of the obtained Ag NPs to less than 10 nm. The mean zeta potential of the fabricated Ag NPs was found to be greater than −30 mV, signifying their stability. The Ag NPs were also found to effectively inhibit bacterial activity. The PLFL technique has proved to be a powerful method for controlling the size of NPs when it is simultaneously associated with a chemical reduction process.


DYNA ◽  
2018 ◽  
Vol 85 (206) ◽  
pp. 69-78 ◽  
Author(s):  
Wilson Agudelo ◽  
Yuliet Montoya ◽  
John Bustamante

El uso de compuestos químicos más biocompatibles y renovables para la obtención de nanopartículas metálicas con propiedades y características deseadas, se convierte en una ruta alternativa para la reducción de riesgos ambientales y del grado de incompatibilidad de estas estructuras al interactuar con modelos biológicos para su posible aplicación en el área de la salud. El propósito de este trabajo se centró en el uso de sacarosa, como agente reductor de nanopartículas de oro y plata al emplear diferentes volúmenes de hidróxido de sodio. Las nanopartículas obtenidas fueron caracterizadas mediante espectrometría UV-visible, microscopía electrónica de transmisión TEM y espectroscopia infrarroja por transformada de Fourier FTIR, la cual permitió determinar los plasmones de resonancia superficial, tamaños de partícula experimentales y teóricos, morfología y cambios estructurales en el agente reductor, así como la influencia del hidróxido de sodio en el proceso de síntesis. Los resultados obtenidos confirman la formación de nanopartículas de oro y plata mediante la previa formación de azúcares reductores. Así mismo, la oxidación del grupo funcional de la glucosa a sales de ácido carboxílico.


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.


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.


Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 874 ◽  
Author(s):  
Janith Weerasinghe ◽  
Wenshao Li ◽  
Rusen Zhou ◽  
Renwu Zhou ◽  
Alexander Gissibl ◽  
...  

Silver nanoparticles have applications in plasmonics, medicine, catalysis and electronics. We report a simple, cost-effective, facile and reproducible technique to synthesise silver nanoparticles via plasma-induced non-equilibrium liquid chemistry with the absence of a chemical reducing agent. Silver nanoparticles with tuneable sizes from 5.4 to 17.8 nm are synthesised and characterised using Transmission Electron Microscopy (TEM) and other analytic techniques. A mechanism for silver nanoparticle formation is also proposed. The antibacterial activity of the silver nanoparticles was investigated with gram-positive and gram-negative bacteria. The inhibition of both bacteria types was observed. This is a promising alternative method for the instant synthesis of silver nanoparticles, instead of the conventional chemical reduction route, for numerous applications.


2011 ◽  
Vol 415-417 ◽  
pp. 747-750
Author(s):  
Bing Xu ◽  
Ren Guo Song ◽  
Chao Wang

In order to study the effects of laser fluence on silver nanoparticles colloid, the silver nanoparticles colloid was prepared by pulsed laser ablation of silver target for 10min in distilled water at different laser fluence. The particles size,morphologies and absorption spectroscopy of the obtained nanoparticles colloid were characterized by ultraviolet to visible (UV-Vis) spectrometer and transmission electron microscopy (TEM), the average diameter and its distribution were analyzed by Image-ProPlus software. The results shown that the average diameter of the silver nanoparticles prepared at the laser fluence of 4.2J/cm2 was the smallest (D=17.54nm), also, the distribution of particle size was narrowest (=36.86nm) and the morphologies were more homogeneous. It was confirmed that the nanoparticles size and shape could be controlled by pulsed laser ablation parameters.


2010 ◽  
Vol 152-153 ◽  
pp. 1771-1774 ◽  
Author(s):  
Jia Zhi Yang ◽  
Ju Wei Yu ◽  
Dong Ping Sun ◽  
Xu Jie Yang

In this work, we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers (BCF) as template. Silver (Ag) nanoparticles with an average diameter of 1.5 nm were well dispersed on BC nanofibers via a simple in situ chemical-reduction between AgNO3 and NaBH4 at relatively low temperature. The bare BCF and as-prepared Ag/BCF hybrid nanofibers were characterized by a range of analytical techniques including transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV–vis absorption spectra (UV–vis). The results reveal that Ag nanoparticles were homogeneously precipitated on the BCF surface. The results indicate that Ag/BCF hybrid nanofibers are promising candidate materials for functional antimicrobial agents.


Chemosensors ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 53 ◽  
Author(s):  
Lu Yu ◽  
Na Li

Nobel metal can be used to form a category of nanoparticles, termed noble metal nanoparticles (NMNPs), which are inert (resistant to oxidation/corrosion) and have unique physical and optical properties. NMNPs, particularly gold and silver nanoparticles (AuNPs and AgNPs), are highly accurate and sensitive visual biosensors for the analytical detection of a wide range of inorganic and organic compounds. The interaction between noble metal nanoparticles (NMNPs) and inorganic/organic molecules produces colorimetric shifts that enable the accurate and sensitive detection of toxins, heavy metal ions, nucleic acids, lipids, proteins, antibodies, and other molecules. Hydrogen bonding, electrostatic interactions, and steric effects of inorganic/organic molecules with NMNPs surface can react or displacing capping agents, inducing crosslinking and non-crosslinking, broadening, or shifting local surface plasmon resonance absorption. NMNPs-based biosensors have been widely applied to a series of simple, rapid, and low-cost diagnostic products using colorimetric readout or simple visual assessment. In this mini review, we introduce the concepts and properties of NMNPs with chemical reduction synthesis, tunable optical property, and surface modification technique that benefit the development of NMNPs-based colorimetric biosensors, especially for the visual quantification. The “aggregation strategy” based detection principle of NMNPs colorimetric biosensors with the mechanism of crosslinking and non-crosslinking have been discussed, particularly, the critical coagulation concentration-based salt titration methodology have been exhibited by derived equations to explain non-crosslinking strategy be applied to NMNPs based visual quantification. Among the broad categories of NMNPs based biosensor detection analyses, we typically focused on four types of molecules (melamine, single/double strand DNA, mercury ions, and proteins) with discussion from the standpoint of the interaction between NMNPs surface with molecules, and DNA engineered NMNPs-based biosensor applications. Taken together, NMNPs-based colorimetric biosensors have the potential to serve as a simple yet reliable technique to enable visual quantification.


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