scholarly journals Deteksi Cepat Fusarium sp. pada Benih Kedelai Menggunakan Metode Spektroskopi Fluoresens

2018 ◽  
Vol 14 (3) ◽  
pp. 97
Author(s):  
Djoko Pujiarto ◽  
Bonny Poernomo Wahyu Soekarno ◽  
Akhiruddin Maddu

Rapid Detection Method for Fusarium sp. on Soybean Seed Using Fluorescence Spectroscopy MethodSeed borne pathogens play an important role as source of inoculum for disease in the field.  Seed health testing is applied in order to prevent risks caused by seed borne pathogen. Fluorescence spectroscopy is a potential technology to be used as detection method for seed borne pathogen. Research was conducted to develop rapid detection protocol for seed borne pathogenic fungus by fluorescence spectroscopy method.  The result showed that fluorescence spectroscopy could detect fluorescence emission of metabolite of Fusarium sp. after soybean seeds were incubated for 24 hr.  Metabolite of Fusarium sp. produced cyan fluorescent at peak wavelength emission 504 nm when excited to violet light (405 nm).  Fusarium sp. displayed typical fluorescence emission spectra which differ from fluorescence emission spectra of growth medium potato dextrose broth (PDB) (502 nm). It was evidenced that fluorescence spectroscopy method can be used to detect pathogenic seed borne fungi.

2001 ◽  
Vol 66 (10) ◽  
pp. 1473-1489 ◽  
Author(s):  
Drahomír Výprachtický ◽  
Věra Cimrová ◽  
Luďka Machová ◽  
Veronika Pokorná

Using the steady-state and time-resolved fluorescence spectroscopy, the behavior of "hairy-rod" oligo- and poly[2,5-bis(hexadecyloxy)-1,4-phenylene]s in tetrahydrofuran solutions was investigated. The materials were prepared by the Yamamoto coupling reaction using zinc as a reducing metal, the nickel(II)/triphenylphosphine complex as a catalyst, and 2,2'-bipyridine as a coligand. The appropriate oligomer fractions were separated by fractional precipitation and characterized by GPC and end group analysis. The fluorescence quantum yield of oligomers and polymers increased with their increasing conjugation length. The fluorescence emission spectra of polymers and longer oligomers exhibited one emission maximum at 390 nm with a single-exponential decay and fluorescence lifetimes (τ) around 1 ns. The substitution in positions 2 and 5 forces the adjacent backbone benzene units out of the plane, which results in twist angles 60-80°, and the bulky substituents exclude the cofacial sandwich-type configuration necessary for excimer formation. However, with shorter oligomers, another emission band at 460 nm appeared. Fluorescence decays at 460 nm were found to be double-exponential with longer excited-state lifetimes [e.g. τ1 = 6.9 ns (76%), τ2 = 2.4 ns (24%)]. With shorter oligomers (dimer, trimer), we assume a sandwich-type configuration with sufficiently close interchain distance and hence the excimer can form. Hydrophobic interactions of long aliphatic side chains in a polar medium play an important role in the excimer formation.


2014 ◽  
Vol 940 ◽  
pp. 11-15
Author(s):  
Jun Qin Feng ◽  
Jun Fang Chen

Zinc nitride films were deposited by ion sources-assisted magnetron sputtering with the use of Zn target (99.99% purity) on 7059 glass substrates. The films were characterized by XRD, SEM and EDS, the results of which show that the polycrystalline zinc nitride thin film can be grown on the glass substrates, the EDS spectrum confirmed the chemical composition of the films and the SEM images revealed that the zinc nitride thin films have a dense structure. Ultraviolet-visible-near infrared spectrophotometer was used to study the transmittance behaviors of zinc nitride thin films, which calculated the optical band gap by Davis Mott model. The results of the fluorescence emission spectra show the zinc nitride would be a direct band gap semiconductor material.


1992 ◽  
Vol 271 ◽  
Author(s):  
Gregory J. Exarhos ◽  
Nancy J. Hess

ABSTRACTIn situ optical methods are reviewed for characterization of phase transformation processes and evaluation of residual stress in solution-deposited metastable oxide films. Such low density films most often are deposited as disordered phases making them prone to crystallization and attendant densification when subjected to increased temperature and/or applied pressure. Inherent stress imparted during film deposition and its evolution during the transformation are evaluated from phonon frequency shifts seen in Raman spectra (TiO2) or from changes in the laser-induced fluorescence emission spectra for films containing rare earth (Sm+3:Y3Al5O12) or transition metal (Cr+3 :Al2O3) dopants. The data in combination with measured increases in line intensities intrinsic to the evolving phase are used to follow crystallization processes in thin films. In general, film deposition parameters are found to influence the crystallite ingrowth kinetics and the magnitude of stress and stress relaxation in the film during the transformation. The utility of these methods to probe crystallization phenomena in oxide films will be addressed.


2012 ◽  
Vol 19 (3) ◽  
pp. 943-947 ◽  
Author(s):  
Z. Parang ◽  
A. Keshavarz ◽  
S. Farahi ◽  
S.M. Elahi ◽  
M. Ghoranneviss ◽  
...  

RSC Advances ◽  
2015 ◽  
Vol 5 (62) ◽  
pp. 50306-50311 ◽  
Author(s):  
Illa Ramakanth ◽  
Jaromír Pištora

Figure showing the effect of pH on CPC gel formation at 25 °C and fluorescence emission spectra of CPC solutions at pH ∼ 11.8.


1994 ◽  
Vol 41 (1) ◽  
pp. 63-72
Author(s):  
T Pawełczyk ◽  
R A Easom ◽  
M S Olson

The effects of various mono- and divalent ions on the pyruvate dehydrogenase complex (PDC) were investigated. To determine the radius of PDC under various conditions a two-dimensional agarose gel electrophoresis technique was used. The radius of PDC cross-linked with glutaraldehyde at ionic strength 0.04 M was calculated to be 22.0 +/- 0.1 nm. The presence of K+, Na+ or HPO4(2-) prevented changes in electromobility and of the calculated radius of PDC induced by alteration in ionic strength. The fluorescence emission spectra of PDC depended on the ionic strength and monovalent cations. The fluorescence intensity of PDC increased in the presence of 80 mM K+, and decreased in the presence of 80 mM Na+ with no shift in the emission maximum wavelength. Changes in the ionic strength to which PDC was exposed resulted in alteration of the UV absorption spectra in the 230 nm region. These alterations were prevented by HPO4(2-), whereas Na+ or K+ ions had no effect on the UV absorption spectrum of PDC.


2018 ◽  
Vol 55 (1) ◽  
pp. 63-67
Author(s):  
Monica Florentina Raduly ◽  
Valentin Raditoiu ◽  
Alina Raditoiu ◽  
Luminita Eugenia Wagner ◽  
Viorica Amariutei ◽  
...  

The seven curcumin derivatives were deposited on palygorskite in order to obtain hybrid materials. The fluorescence emission spectra of the obtained materials show a decrease in fluorescence intensity relative to the respective dyes, due to the environments around the dyestuff molecules created in the host matrices. Absorption studies show the best adsorption on the inorganic matrix, for the compounds with the hydroxyl groups. Correlating fluorescence spectra of hybrid materials with the results for absorption spectra of the dyes adsorbtion on the surface of the clay lead to the conclusion that a high percentage of the adsorbed dye had the effect of fluorescence quenching. Thus, it was confirmed that the fluorescent properties of hybrid materials depend on the interactions established between the fluorescent dyestuff and the inorganic network.


2015 ◽  
Vol 18 (3) ◽  
pp. 155-158 ◽  
Author(s):  
Yuan Zhou ◽  
Qiming Liu ◽  
Yuao Zhang

Two new zinc(II) complexes have been prepared by reaction of 2-(2’-Hydroxyphenyl)-2-oxazoline(Hoz) with Zn(acac)2 and ZnCl2 respectively. The complexes are characterized by IR and X-ray crystallography. Complex 1 is dinuclear zinc structure bridged by the oxygen atoms from oz- ligand and acac- ligand as terminal chelating ligand. Complex 2 is tetranuclear zinc structure bridged by both μ2-oxygen from oz- ligand and μ3-methoxide. 1 crystalizes in P21 space group with crystallographic parameters: a=9.3842Å19), b=13.5840 Å30), c=11.1380 Å20), β=96.250°(30). 2 crystalizes in P-1 space group with crystallographic parameters: a=9.5517Å(19), b=11.1234Å(22), c=11.1826Å(22), α=102.820°(30), β=114.988°(30), γ=100.806°(30). The UV absorption and fluorescence emission spectra are measured on the methanol solution and solid state of complex 1 and it shows strong luminescence.


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