scholarly journals Biosynthesis of Gold Nanoparticles Using Litsea cubeba Fruit Extract for Catalytic Reduction of 4-Nitrophenol

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Van-Dat Doan ◽  
Anh Tai Thieu ◽  
Thanh-Danh Nguyen ◽  
Van-Cuong Nguyen ◽  
Xuan-Thang Cao ◽  
...  

This work describes a simple single-step method for green synthesis of colloidal gold nanoparticles (AuNPs) using Litsea cubeba (LC) fruit extract as a reducing as well as stabilizing agent simultaneously. Major parameters affecting the formation of LC-AuNPs, including gold ion concentration, reaction time, and reaction temperature were optimized using ultraviolet-visible (UV-Vis) measurements at a characteristic maximum absorbance of 535 nm. The functional groups responsible for reducing gold ions and capping AuNPs were examined by Fourier-transform infrared (FTIR) spectroscopy. Powder X-ray diffraction (XRD) analysis revealed the crystalline nature of AuNPs. Transmission electron microscopy (TEM) measurements showed that the biosynthesized LC-AuNPs were mostly spherical with an average size of 8-18 nm. The nanoparticles also demonstrated excellent ultrarapid catalytic activity for the complete reduction of 4-nitrophenol to p-aminophenol in the presence of NaBH4 within 10 min with a reaction rate constant of 0.348 min-1.

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1999
Author(s):  
Kaushik Kumar Bharadwaj ◽  
Bijuli Rabha ◽  
Siddhartha Pati ◽  
Bhabesh Kumar Choudhury ◽  
Tanmay Sarkar ◽  
...  

The green synthesis of silver nanoparticles (AgNPs) has currently been gaining wide applications in the medical field of nanomedicine. Green synthesis is one of the most effective procedures for the production of AgNPs. The Diospyros malabarica tree grown throughout India has been reported to have antioxidant and various therapeutic applications. In the context of this, we have investigated the fruit of Diospyros malabarica for the potential of forming AgNPs and analyzed its antibacterial and anticancer activity. We have developed a rapid, single-step, cost-effective and eco-friendly method for the synthesis of AgNPs using Diospyros malabarica aqueous fruit extract at room temperature. The AgNPs began to form just after the reaction was initiated. The formation and characterization of AgNPs were confirmed by UV-Vis spectrophotometry, XRD, FTIR, DLS, Zeta potential, FESEM, EDX, TEM and photoluminescence (PL) methods. The average size of AgNPs, in accordance with TEM results, was found to be 17.4 nm. The antibacterial activity of the silver nanoparticles against pathogenic microorganism strains of Staphylococcus aureus and Escherichia coli was confirmed by the well diffusion method and was found to inhibit the growth of the bacteria with an average zone of inhibition size of (8.4 ± 0.3 mm and 12.1 ± 0.5 mm) and (6.1 ± 0.7 mm and 13.1 ± 0.5 mm) at 500 and 1000 µg/mL concentrations of AgNPs, respectively. The anticancer effect of the AgNPs was confirmed by MTT assay using the U87-MG (human primary glioblastoma) cell line. The IC50 value was found to be 58.63 ± 5.74 μg/mL. The results showed that green synthesized AgNPs exhibited significant antimicrobial and anticancer potency. In addition, nitrophenols, which are regarded as priority pollutants by the United States Environmental Protection Agency (USEPA), can also be catalytically reduced to less toxic aminophenols by utilizing synthesized AgNPs. As a model reaction, AgNPs are employed as a catalyst in the reduction of 4-nitrophenol to 4-aminophenol, which is an intermediate for numerous analgesics and antipyretic drugs. Thus, the study is expected to help immensely in the pharmaceutical industries in developing antimicrobial drugs and/or as an anticancer drug, as well as in the cosmetic and food industries.


2014 ◽  
Vol 938 ◽  
pp. 182-191
Author(s):  
P. Divya ◽  
A. Sudarvizhi ◽  
K. Pandian

A single step method for the synthesis of gold nanoparticles decorated graphene oxide nanocomposite using aniline as reducing agent has been developed. The composite was characterized using FE-SEM, UV-Vis and FT-IR and XRD analysis. The electron transfer behavior of the modified electrodes was investigated in a redox probe using cyclic voltammetry. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed to evaluate the electrochemical properties of AuNPs/GO/GCE towards the electrochemical oxidation of tryptophan. A calibration graph was constructed by plotting the concentration of tryptophan against the peak current. Under the optimum experimental conditions, the oxidation peak currents were measured by varying the tryptophan concentrations. The resulting sensor displays an excellent repeatability and long-term stability.


2018 ◽  
Vol 15 (35) ◽  
pp. 109-116
Author(s):  
Falah A-H. Mytlak

Gold nanoparticles AuNPs have proven to be powerful tools in various nanomedicine applications, because of their photo-optical distinctiveness and biocompatibility. Noble metal gold nanoparticles was prepared by pulsed laser ablation method (1064-Nd: YAG with various Laser power from 200 to 800 mJ and 1 Hz frequency) in distil water. The process was characterized using UV-VIS absorption spectroscopy. Morphology and average size of nanoparticles were estimated using AFM and X-ray diffraction (XRD) analysis which show the nature of gold nanoparticles (AuNPs). Antibacterial activity of gold nanoparticles as a function of particles concentration against gram negative bacterium Escherichia coli and gram positive bacterial Staphylococcus aureus was carried out in solid growth media. Gold nanoparticles show high antibacterial activity with zone of inhibition. Antibacterial activities of the synthesized Au nanoparticles were assessed by agar well diffusion method. The stabilized AuNPs exhibited excellent antibacterial sensitivity (12-27 mm) to E. coli and (26-38mm) to Staph aureus.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Van Thuan Le ◽  
Van-Cuong Nguyen ◽  
Xuan-Thang Cao ◽  
Tan Phat Chau ◽  
Thi Dung Nguyen ◽  
...  

The green biosynthesis of metal nanoparticles (MNPs) has been proved to have many advantages over other methods due to its simplicity, large-scale production, ecofriendly approach, and high catalytic efficiency. This work describes a single-step technique for green synthesis of colloidal silver (AgNPs) and gold nanoparticles (AuNPs) using the extract from Caulis Spatholobi stems. Ultraviolet-visible spectroscopy measurements were used to optimize the main synthesis factors, including metal ion concentration, reaction time, and reaction temperature via surface plasmon resonance phenomenon. Fourier-transform infrared spectroscopy showed the possible functional groups responsible for reducing and stabilizing the synthesized MNPs. The powder X-ray diffraction and selected area electron diffraction analysis confirmed the crystalline nature of the biosynthesized MNPs. High-resolution transmission electron microscopy revealed the spherical shape of MNPs with an average size of 10-20 nm. The obtained MNPs also exhibited the enhanced catalytic activity in the reduction of 2-nitrophenol and 3-nitrophenol.


2021 ◽  
Vol 22 (22) ◽  
pp. 12155
Author(s):  
Mariapompea Cutroneo ◽  
Vladimir Havranek ◽  
Anna Mackova ◽  
Petr Malinsky ◽  
Letteria Silipigni ◽  
...  

Typically, polymeric composites containing nanoparticles are realized by incorporating pre-made nanoparticles into a polymer matrix by using blending solvent or by the reduction of metal salt dispersed in the polymeric matrix. Generally, the production of pre-made Au NPs occurs in liquids with two-step processes: producing the gold nanoparticles first and then adding them to the liquid polymer. A reproducible method to synthetize Au nanoparticles (NPs) into polydimethylsiloxane (PDMS) without any external reducing or stabilizing agent is a challenge. In this paper, a single-step method is proposed to synthetize nanoparticles (NPs) and at the same time to realize reproducible porous and bulk composites using laser ablation in liquid. With this single-step process, the gold nanoparticles are therefore produced directly in the liquid polymer. The optical properties of the suspensions of AuNPs in distilled water and in the curing agent have been analyzed by the UV-VIS spectroscopy, employed in the transmission mode, and compared with those of the pure curing agent. The electrical dc conductivity of the porous PDMS/Au NPs nanocomposites has been evaluated by the I–V characteristics. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis have monitored the composition and morphology of the so-obtained composites and the size of the fabricated Au nanoparticles. Atomic force microscopy (AFM) has been used to determine the roughness of the bulk PDMS and its Au NP composites.


Author(s):  
Amel Taha ◽  
Mustaffa Shamsuddin

Nanomaterials are attracting a lot of attention nowadays as they show different chemical and physical properties that are dependent on their size and shape. Different techniques have been used for synthesis metal nanoparticles but the use of plants for synthesis of nanoparticles could be advantageous over other environmentally methods as this eliminates the cost and the non toxicity is main feature. Here a simple biosynthesis approach was applied and gold nanoparticles were synthesized by using psidium guajava leaf extract as reducing and capping agent. Two different parameters were studied which are the metal ion concentration and volume of plant broth. The synthesis of gold nanoparticles was also monitored as function of reaction time. The formation of gold nanoparticles was monitored by UV-Vis spectrophotometer and the size of particles was confirmed by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) techniques. TEM analysis showed that the AuNPs were mostly spherical in shape with an average size of 15 nm. Fourier Transform Infrared (FTIR) spectroscopy that the active biomolecules present in the Psidium guajava leaf extract act as capping and stabilizing agent for the AuNPs.


2017 ◽  
Vol 1 (3) ◽  
Author(s):  
Shib Shankar Dash ◽  
Braja Gopal Bag ◽  
Abhisek Midya

The fruit extract of Ficus carica Linn (Dumur) is rich in different types of plant secondary metabolites such as terpenoids, polyphenols including flavanoids, etc. We have demonstrated the use of the fruit extract for the synthesis of gold nanoparticles in water at room temperature under very mild conditions. There was no need of additional stabilizing or capping agents and the synthesis of the gold nanoparticles was complete in several minutes. The gold nanoparticles were characterized by HRTEM, EDX, SAED, Surface Plasmon Resonance Spectroscopy and X-Ray diffraction studies. The freshly prepared gold nanoparticles have been used as an efficient catalyst for the sodium borohydride reduction of 4-nitrophenol to 4-aminophenol in water at room temperature and the kinetics of the reduction reaction have been studied spectrophotometrically.


1983 ◽  
Vol 49 (01) ◽  
pp. 024-027 ◽  
Author(s):  
David Vetterlein ◽  
Gary J Calton

SummaryThe preparation of a monoclonal antibody (MAB) against high molecular weight (HMW) urokinase light chain (20,000 Mr) is described. This MAB was immobilized and the resulting immunosorbent was used to isolate urokinase starting with an impure commercial preparation, fresh urine, spent tissue culture media, or E. coli broth without preliminary dialysis or concentration steps. Monospecific antibodies appear to provide a rapid single step method of purifying urokinase, in high yield, from a variety of biological fluids.


Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 473
Author(s):  
Prabu Kumar Seetharaman ◽  
Rajkuberan Chandrasekaran ◽  
Rajiv Periakaruppan ◽  
Sathishkumar Gnanasekar ◽  
Sivaramakrishnan Sivaperumal ◽  
...  

To develop a benign nanomaterial from biogenic sources, we have attempted to formulate and fabricate silver nanoparticles synthesized from the culture filtrate of an endophytic fungus Penicillium oxalicum strain LA-1 (PoAgNPs). The synthesized PoAgNPs were exclusively characterized through UV–vis absorption spectroscopy, Fourier Transform Infra-Red spectroscopy (FT-IR), X-ray powder diffraction (XRD), and Transmission Electron Microscopy (TEM) with energy dispersive X-ray spectroscopy (EDX). The synthesized nanoparticles showed strong absorbance around 430 nm with surface plasmon resonance (SPR) and exhibited a face-centered cubic crystalline nature in XRD analysis. Proteins presented in the culture filtrate acted as reducing, capping, and stabilization agents to form PoAgNPs. TEM analysis revealed the generation of polydispersed spherical PoAgNPs with an average size of 52.26 nm. The PoAgNPs showed excellent antibacterial activity against bacterial pathogens. The PoAgNPs induced a dose-dependent cytotoxic activity against human adenocarcinoma breast cancer cell lines (MDA-MB-231), and apoptotic morphological changes were observed by dual staining. Additionally, PoAgNPs demonstrated better larvicidal activity against the larvae of Culex quinquefasciatus. Moreover, the hemolytic test indicated that the as-synthesized PoAgNPs are a safe and biocompatible nanomaterial with versatile bio-applications.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1426
Author(s):  
Tomáš Remiš ◽  
Petr Bělský ◽  
Tomáš Kovářík ◽  
Jaroslav Kadlec ◽  
Mina Ghafouri Azar ◽  
...  

In this work, advanced polymer nanocomposites comprising of polyvinyl alcohol (PVA) and nanodiamonds (NDs) were developed using a single-step solution-casting method. The properties of the prepared PVA/NDs nanocomposites were investigated using Raman spectroscopy, small- and wide-angle X-ray scattering (SAXS/WAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It was revealed that the tensile strength improved dramatically with increasing ND content in the PVA matrix, suggesting a strong interaction between the NDs and the PVA. SEM, TEM, and SAXS showed that NDs were present in the form of agglomerates with an average size of ~60 nm with primary particles of diameter ~5 nm. These results showed that NDs could act as a good nanofiller for PVA in terms of improving its stability and mechanical properties.


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