scholarly journals Mycosynthesis of biocompatible gold nanoparticles using Penicillium sp for bromothymol blue degradation

Biomedicine ◽  
2020 ◽  
Vol 39 (2) ◽  
pp. 346-352
Author(s):  
B. S. Srinath ◽  
S. Gowda Ganesh ◽  
P Shastry Rajesh ◽  
K. Byrappa
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Color Change ◽  
Bromothymol Blue ◽  
Fungal Culture ◽  
Visible Spectroscopy ◽  
Au Nps ◽  
Penicillium Sp ◽  
Haemolytic Assay ◽  
Uv Visible

Introduction and Aim: The Biosynthesis of Gold nanoparticles (Au NPs) is an eco-friendly, cost effective and nontoxic alternative to chemical and physical methods. In the present study synthesis of Au NPs was performed by using a fungi Penicillium sp. isolated from agriculture soil. Materials and Methods: Fungi was isolated from the agricultural field and inoculated into Sabouraud Dextrose broth and incubated at 28º C in a shaker at 180 rpm for 96 to 120 hours. After incubation, the fungal culture was filtered and centrifuged, obtained fungal cell free extracts treated with 1mM gold salt (HAuCl4). The synthesis of Au NPs was confirmed by UV–visible spectroscopy and particles size was measured using Dynamic Light Scattering (DLS). Haemolytic assay of Au NPs was carried out using Chicken RBCs and results measured at 540 nm in UV-visible spectrophotometer. To study catalytic activity, Bromothymol blue (BB) was subjected to reduction by using sodium borohydride (NaBH4, 5.28X10-2 M) in the presence of Au NPs. Then the color change was monitored by visual observation. Results: The synthesis of Au NPs was preliminary observed by a color change from yellow to purple and confirmed by a peak at 560 nm using a UV–visible spectroscopy. The DLS analysis showed that the Au NPs were poly-dispersed and size ranges from 130 to 150 nm. The biosynthesised Au NPs was studied  for their biocompatibility and dye degradation properties. Conclusion: The obtained results revealed that biosynthesized Au NPs shows a minimum level of toxicity to chicken erythrocytes and good catalytic activity towards the degradation of hazardous dye bromothymol blue. These nanoparticles could be potentially useful in various applications in medical and environmental fields.  

scholarly journals IN VITRO CYTOTOXICITY OF BIOSYNTHESIZED GOLD NANOPARTICLES FROM SHELLS OF PISTACIA VERA L

2018 ◽  
Vol 10 (4) ◽  
pp. 162
Author(s):  
Madhumithra S. K. ◽  
Balashanmugam P. ◽  
Mosachristas K. ◽  
Tamil Selvi A. ◽  
Subashini R.
Keyword(s):  
Gold Nanoparticles ◽  
Anticancer Activity ◽  
Cell Lines ◽  
Cancer Cell ◽  
Color Change ◽  
Cancer Cell Lines ◽  
Pistacia Vera ◽  
Visible Spectroscopy ◽  
Uv Visible

Objective: To synthesize the gold nanoparticles by a biological method using the extract obtained from the shells of Pistacia vera (P. vera) and to study its effective role in the anticancer activity.Methods: The synthesis of gold nanoparticles using the extract obtained from the shells of Pistacia vera was confirmed by the color change and substantiating the same using ultraviolet (UV) visible spectroscopy. The size and the shape of the particles were studied using field emission scanning electron microscopy (FESEM). The stability of the nanoparticles was assessed by using the UV visible spectroscopy and Fourier-transform infrared spectroscopy (FTIR). The anticancer activity of the gold nanoparticles on the cancer cell lines was studied on PA1 ovarian cancer cell lines using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Nature of cell death was analyzed using the fluorescence microscopy.Results: The ruby red color confirmed the formation of gold nanoparticles and it was substantiated by the absorption peak at 543.2 nm in the UV visible spectroscopy. The gold nanoparticles synthesized from the Pistacia vera shell showed the spherical shape and were in the size of around 10-40 nm when analyzed with FESEM. The different functional groups were indicated in the FTIR spectra which were consisting of phenol, alcohol, alkenes and aromatics.Conclusion: The synthesis of the gold nanoparticle using the extract obtained from the shells of Pistacia vera has effective anticancer activity.

Biosynthesis of Gold Nanoparticles with Serratia marcescens Bacteria

2015 ◽  
Vol 1132 ◽  
pp. 19-35
Author(s):  
S.O. Dozie-Nwachukwu ◽  
J.D. Obayemi ◽  
Y. Danyo ◽  
G. Etuk-Udo ◽  
N. Anuku ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Serratia Marcescens ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Color Changes ◽  
Transmission Electron ◽  
Helium Ion ◽  
Ph Conditions ◽  
Uv Visible ◽  
Ion Microscopy

This paper presents the biosynthesis of gold nanoparticles from the bacteria, Serratia marcescens.The intra-and extra-cellular synthesis of gold nanoparticles is shown to occur over a range of pH and incubation times in cell-free exracts and biomass ofserratia marcescensthat were reacted with 2.5mM Tetrachloroauric acid (HAuCl4). The formation of gold nanoparticles was identified initially via color changes from yellow auro-chloride to shades of red or purple in gold nanoparticle solutions. UV-Visible spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray spectroscopy (EDS), Helium Ion Microscopy (HIM) and Dynamic Light Scattering (DLS) were also used to characterize gold nanoparticles produced within a range of pH conditions. The results show clearly that the production of gold nanoparticles from cell-free extracts require shorter times than the production of gold nanoparticles from the biomass.

Synthesis and Characterization of Gold Nanoparticles Synthesized in Gel and Paper by Electrolysis

2019 ◽  
Vol 824 ◽  
pp. 163-167
Author(s):  
Pema Dechen ◽  
Ekasith Somsook
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gold Nanoparticles ◽  
Room Temperature ◽  
Synthesis And Characterization ◽  
Visible Spectroscopy ◽  
Gold Leaf ◽  
Uv Visible ◽  
Scanning Electron

In this report, synthesis and characterization of gold nanoparticles (AuNPs) from gold leaf by electrolysis in two different media (gel and paper) in presence of sodium chloride (NaCl), glucose (C6H12O6) and polyvinyl pyrrolidone (PVP) at room temperature were investigated. Graphite was used as two electrodes, NaCl was used as an electrolyte, C6H12O6 was used as reducing agent and PVP was used as stabilizer to control the aggregation of the nanoparticles. UV-Visible spectroscopy (UV-Vis) and scanning electron microscopy (SEM) were used to confirm the characteristics and morphologies of the synthesized AuNPs.

scholarly journals Amplified visual immunosensor integrated with nanozyme for ultrasensitive detection of avian influenza virus

2017 ◽  
Author(s):  
Syed Rahin Ahmed ◽  
Suresh Neethirajan
Keyword(s):  
Gold Nanoparticles ◽  
Influenza Virus ◽  
Catalytic Activity ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Limit Of Detection ◽  
Blue Color ◽  
Au Nps ◽  
Influenza Virus A ◽  
Practical Applications

ABSTRACTNanomaterial-based artificial enzymes or nanozymes exhibits superior properties such as stability, cost effectiveness and ease of preparation in comparison to conventional enzymes. However, the lower catalytic activity of nanozymes limits their sensitivity and thereby practical applications in the bioanalytical field. To overcome this drawback, herein we propose a very simple but highly sensitive, specific and low-cost dual enhanced colorimetric immunoassay for the detection of avian influenza virus A (H5N1) through facile in situ synthesis of gold nanoparticles and their peroxidase-like enzymatic activity. 3,3’,5,5’-Tetramethylbenzidine (TMBZ) was used as a reducing agent to produce gold nanoparticles (Au NPs) from a viral target-specific antibody-gold ion complex. The developed blue color from the sensing design was further amplified through catalytic activity of Au NPs in presence of TMBZ–hydrogen peroxide (H2O2) complex. The developed dual enhanced colorimetric immunosensor enables the detection of avian influenza virus A (H5N1) with a limit of detection (LOD) of 1.11 pg/mL. Our results further confirms that the developed assay has superior sensitivity than the conventional ELISA method, plasmonic-based bioassay and commercial flu diagnostic kits.

Synthesis of Gold Nanoparticles Using Glutamic Acid as a Reductor and Capping Agent

2020 ◽  
Vol 840 ◽  
pp. 472-477
Author(s):  
Naura Nadhifah ◽  
Wening Rara Pratita ◽  
Eko Sri Kunarti ◽  
Nuryono Nuryono ◽  
Sri Juari Santosa
Keyword(s):  
Gold Nanoparticles ◽  
Acid Solution ◽  
Glutamic Acid ◽  
Color Change ◽  
Reaction Times ◽  
Chloroauric Acid ◽  
Optimum Synthesis ◽  
Transmission Electron ◽  
Particle Size Analyzer ◽  
Uv Visible

The synthesis of gold nanoparticles (AuNPs) was carried out by reacting chloroauric acid [AuCl4]‒ and glutamic acid solution in a water bath at 80 °C. The reaction was confirmed by the color change from colorless solution into pink. Various concentrations of the glutamic acid solution, reaction times and pH were examined to determine the optimum condition of AuNPs synthesis. The AuNPs colloid was characterized by UV-Visible spectrophotometer at wavelength 350-800 nm, particle size analyzer (PSA) and transmission electron microscope (TEM). The optimum synthesis condition for obtained [AuCl4]‒ was 4 mM glutamic acid solution at pH 11 and 60 min reaction. TEM results showed that the particles were round in shape with the article size indicated by PSA was 40 nm.

Effect of Ni Reducibility on Anisole Hydrodeoxygenation Activity in the La-Ni/γ-Al2O3 Catalytic System

2019 ◽  
Vol 18 (2) ◽  
Author(s):  
Brett Pomeroy ◽  
Teri Doxtator ◽  
Jose E. Herrera ◽  
Dominic Pjontek
Keyword(s):  
Catalytic Activity ◽  
Catalytic System ◽  
Catalyst Surface ◽  
Reaction Pathway ◽  
Catalyst Characterization ◽  
Temperature Programmed Reduction ◽  
Visible Spectroscopy ◽  
Uv Visible ◽  
Temperature Programmed

Abstract The effect of lanthanum addition on the activity of a series of Ni/γ-Al2O3 catalysts for anisole hydrodeoxygenation (HDO) was evaluated. Catalyst characterization using hydrogen temperature-programmed reduction (H2-TPR) and UV-visible spectroscopy suggests that lanthanum incorporation results in the formation of larger metallic Ni domains in the catalyst surface, which in turn favour the direct anisole hydrogenation pathway to methoxycyclohexane. Despite the improvements to reducibility that resulted from the incorporation of La, the catalysts displayed lower selectivity towards cyclohexane, independent of total nickel loading. The catalytic activity results were rationalized in terms of a proposed reaction pathway where anisole is initially hydrogenated followed by sequential deoxygenation steps.

scholarly journals Green Synthesis of Gold Nanoparticles from Coprinus comatus, Agaricaceae, and the Effect of Ultraviolet Irradiation on Their Characteristics

2021 ◽  
Vol 18 (8) ◽  
Author(s):  
Ghassan Adnan NAEEM ◽  
Ahmed Saadoun JALOOT ◽  
Mustafa Nadhim OWAID ◽  
Rasim Farraj MUSLIM
Keyword(s):  
Gold Nanoparticles ◽  
Uv Irradiation ◽  
Color Change ◽  
Visible Spectrum ◽  
Face Centered Cubic ◽  
Coprinus Comatus ◽  
Light Yellow ◽  
Uv Visible ◽  
Face Centered ◽  
Nanoscale Range

The present research aims to produce gold nanoparticles (AuNPs) from the aqueous extract of locally isolated mushroom Coprinus comatus from Hit city, Iraq. Its properties were studied using the optical vision, UV-Vis, EDX, XRD, FTIR, AFM, and Zetasizer analyses. The exposure of the colloidal solution of AuNPs to UV radiation was investigated for 1, 2, and 3 h. The results showed the color change of the interaction mixture from light yellow to purple after 25 min. The lambda max of the absorbance reached 530 nm using UV-Visible spectrum as evident in the formation of AuNPs. FTIR spectra revealed the presence of functional groups related to peptides, proteins, flavonoids, monosaccharides, and phenolic compounds, which reduced gold ions. The EDX technique showed that the formed nanoparticles were AuNPs. XRD results showed that AuNPs have a face-centered cubic (fcc) crystal. The UV irradiation at different times led to an increase in the intensity of absorbance and sizes of AuNPs from 17.39 nm before the irradiation and switched to 58.16, 59.13, and 47.35 nm after 1, 2, and 3 h, respectively, but their sizes remained within the nanoscale range (less than 100 nm). In conclusion, the best result was observed after about an hour on the effects of UV irradiation on sizes of AuNPs, which reached smaller nanoparticles compared with times 2 and 3 h.

scholarly journals Synthesis, characterization and functional evaluation of gold nanoparticles prepared using Dovyalis abyssinica leaf extracts as reducing and surface capping agent

2021 ◽  
Vol 14 (2) ◽  
pp. 171-190
Author(s):  
Abera Beyene Gebresilassie ◽  
Adam Mekonnen Engida
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Plant Extract ◽  
Radical Scavenging ◽  
Diffraction Spectrum ◽  
Functional Evaluation ◽  
Capping Agent ◽  
Aqueous Fraction ◽  
Au Nps ◽  
Surface Capping

Green synthesis of nanoparticles using plants and microorganisms is biologically safe, cost effective, and environmentally friendly technology. Gold nanoparticles (Au NPs) were synthesized using aqueous extracts of leaves of Dovyalis abyssinica as reducing and surface capping agent and the catalytic activity, antibacterial action and antioxidant potential of the synthesized AU NPs were evaluated. Firstly, HAuCl4 was synthesized in the laboratory from metallic gold and hydrochloric acid using a predesigned method. Secondly, Au NPs was synthesized by mixing HAuCl4 and the plant extract at 45 oC with a digestion time of 1 h. The size of the nanoparticles was modulated by varying the ratio of the plant extract and HAuCl4 with known concentrations. The synthesized Au NPs showed strong absorption around 540 nm which lies in the characteristic absorption region of Au metal nanoparticles (520–580 nm). The X-ray diffraction spectrum of the synthesized Au NPs showed characteristic crystalline structures of gold. The scanning electron spectroscopy images of the synthesized Au NPS revealed the presence of mixed shapes predominantly of irregular shapes and a particle size analyzer displayed an average size of 63.13 nm. The fourier-transform infrared spectrum of Au NPS confirmed the presence of amine, carbonyl and hydroxyl functional groups as surface capping molecules. Although the synthesized Au NPs showed poor bacterial growth inhibition activity on two selected bacteria, it demonstrated excellent free radical scavenging activity against 2, 2-Diphenyl-2-picrylhydrazyl (DPPH) radical and good catalytic activity for degrading bromothymol blue and methyl red compounds. In contrast to the hexane and ethyl acetate extracts, the aqueous fraction was identified as powerful reducing fraction for the synthesis of Au NPs in this experiment. 

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