Spectrochim Acta A Mol Biomol Spectrosc
November 2022
There is a need for simple spectrofluorimetric method for detection of glycogen molecule based on binding to nanogold. Here we propose such a quantification method for glycogen using cyanobacteria as a biological model. Biologically, two strains of cyanobacteria were selected based on their previously tested nanogold biosynthetic abilities.
View Article and Find Full Text PDFBackground: Cyanobacteria are considered as green nano-factories. Manipulation of the size of biogenic silver nanoparticles is needed to produce particles that suit the different applications such as the use as antibacterial agents. The present study attempts to manipulate the size of biosynthesized silver nanoparticles produced by cyanobacteria and to test the different-sized nanoparticles against pathogenic clinical bacteria.
View Article and Find Full Text PDFIntranasal route offers a direct nose-to-brain delivery via olfactory and trigeminal nerves and minimizes the systemic exposure of the drug. Although reliable and non-invasive, intranasal administration of lipophilic neuroprotective agents for brain targeting is still challenging. Literature focuses on naturally-derived compounds as a promising therapeutics for chronic brain diseases.
View Article and Find Full Text PDFsp., a coccoid, unicellular, nitrogen-fixing and hydrogen-producing cyanobacterium, has been used in this study to biosynthesize customized gold nanoparticles under certain chemical conditions. The produced gold nanoparticles had a characteristic absorption band at 525-535 nm.
View Article and Find Full Text PDFTo the best of our knowledge, cyanobacterial strains from the Arabian Gulf have never been investigated with respect to their potential for nanoparticle production. was isolated from the AlOqair area, Al-Ahsa Government, Eastern Province, Kingdom of Saudi Arabia. The cyanobacterium was initially incubated with 1500 mg/mL of HAuCl₄ for two days.
View Article and Find Full Text PDFA simple and sensitive spectrofluorimetric method for determination of atenolol (ATE) using gold nanoparticles (AuNPs) was developed. The method is based on the quenching effect of atenolol on photoluminescence of AuNPs at λem = 705 nm. Variables affecting luminescence of gold nanoparticles such as the solvent, pH value and surfactant were studied and optimized.
View Article and Find Full Text PDFNovel chitosan-ZnO composites have been synthesized as luminescent taggants for cellulosic materials. The synthesized chitosan-ZnO nanospheres (CS-ZnO NS), chitosan-ZnO-oleic acid quantum dots (CS-ZnO-oleic QD) and chitosan-ZnO-oleic acid:Eu(3+) doped nanorods (CS-ZnO-oleic:Eu(3+) NR) were characterized by X-ray diffraction, photoluminescence spectroscopy, FTIR spectroscopy and transmission electron microscopy. The prepared luminescent CS-ZnO composites were used in printing paste and applied to different types of papers and textiles by using screen printing technique.
View Article and Find Full Text PDFThe chiral recognition phenomenon was observed in enantioselective and excited-state energy transfer processes. Based on bimolecular luminescence quenching kinetics for a system containing chiral molecules, the quenching efficiency was evaluated by Stern-Volmer equation for a system containing a chiral R(+) and S(-) resolved quencher species. The utility of this methodology is confirmed by examining the enantio-selective excited-state quenching between Eu(dpa)(3) complex (where dpa = pyridine-2,6-dicarboxylate) acting as the energy donor to R(+)-1,1-Bi(2-Naphthol) and S(-)-1,1-Bi(2-naphthol) as the energy acceptor was studied in solution.
View Article and Find Full Text PDFDrought is a serious abiotic stress, causes worldwide intensive reduction in crop growth and productivity. Plants in contrast to other organisms, do not enjoy the luxury of being able to change their environment or seeking shelters. In this investigation, wheat grains were pre-soaked for 12h in salicylic acid (SA) and/or thiourea (ThU) prior they were left to grow in dry land (40% field water capacity) until harvest.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2010
Clozapine drug is photo-stable under irradiation of light for a long time, so we can store it in difficult and hot conditions. In addition the activity of clozapine is inhibited of the absorption spectra in the presence of glucose and enhanced in the presence of iron(III). We succeeded in detecting the concentration of clozapine in the range 1-60x10(-9)M using Eu(III)-dipicolinic acid complex as photo probe type and using Stern-Völmer equation to determine the Stern-Völmer constant, critical radius and the mechanism of quenching of luminescence of Eu(III)-dipicolinic acid complex is found to be of dipolar-dipolar interaction.
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