Возможности и перспективы биосенсорных технологий в анализе продуктов питания

Existing developments in the field of biosensor technologies with the possibility of practical application for establishing food safety indicators were considered. The classification of biosensors is described depending on the physical phenomena underlying its work, the essence and examples of specific developments for the determination of microorganisms, heavy metals and antibiotics in food products are presented. Prospects of biosensor technologies in the food industry are estimated.Рассмотрены существующие разработки в области биосенсорных технологий с возможностью практического применения для установления показателей безопасности продуктов питания. Приведена классификация биосенсоров в зависимости от физических явлений, лежащих в основе его работы, суть и примеры конкретных разработок для определения микроорганизмов, тяжелых металлов и антибиотиков в пищевой продукции. Оценены перспективы биосенсорных технологий в пищевой промышленности

Association of gold nanorods in water solutions: Influence of globular proteins

By the absorption spectroscopy method, optical properties of gold nanorods (10 × 38 nm) and their interaction with globular protein bovine hemoglobin and bovine serum albumin were investigated. Nanorod behavior was studied in water solution and in solution of 97 mM NaCl under ultrasound action during 90 min and results were then compared. In water solutions, nanorod coagulation (aggregation) was observed with reduced optical density of the longitudinal plasmon band widening at λ > 800 nm. In NaCl solution, absorption spectra evolution had a complex character and was in some degree analogous to the result that was obtained for two-dimensional grids of gold nanoparticles when changing the distance between them. By interacting with serum albumin, stabilization of colloid solution and dissociation of nanorod aggregates were observed. © 2012 Pleiades Publishing, Ltd

Association of gold nanorods in water solutions: Influence of globular proteins

By the absorption spectroscopy method, optical properties of gold nanorods (10 × 38 nm) and their interaction with globular protein bovine hemoglobin and bovine serum albumin were investigated. Nanorod behavior was studied in water solution and in solution of 97 mM NaCl under ultrasound action during 90 min and results were then compared. In water solutions, nanorod coagulation (aggregation) was observed with reduced optical density of the longitudinal plasmon band widening at λ > 800 nm. In NaCl solution, absorption spectra evolution had a complex character and was in some degree analogous to the result that was obtained for two-dimensional grids of gold nanoparticles when changing the distance between them. By interacting with serum albumin, stabilization of colloid solution and dissociation of nanorod aggregates were observed. © 2012 Pleiades Publishing, Ltd

Microwave-Assisted Synthesis of Cerium Doped Zno Nanostructures and Its Optical Properties

In this research we attempted to synthesize zinc oxide nanostructures doped with REE cerium by microwave-assisted method. The article presents the results obtained with different pH values of the processed solutions, the time of exposure to microwave irradiation, as well as the results of the application of cyclic irradiation exposure. Samples studied by fluorescence spectroscopy and scanning electron microscopy. © 2020 IOP Publishing Ltd

Enhancement of intrinsic protein luminescence in nanosized complex

[No abstract available

Effect of DNA on the optical properties of ZnO:SiO2:La3+films

ZnO-SiO2 composite films doped with La3+ ions (0.1%-5.0% mass.) were obtained using the sol-gel method. The absorption and ultraviolet luminescence spectra of the films, as well as the change in spectral characteristics under the influence of DNA, were studied. Doping of ZnO:SiO2 films with La3+ ions leads to an increase in the transmittance in the UV range (λ = 357 nm) from 4.5% (for undoped films) to 32%-34%, and the transmittance is inversely proportional to the amount of dopant. In all doped films, the optical band gap increases in comparison with undoped films (3.35 eV) and amounts to 3.830-3.853 eV. The application of DNA to the surface weakly affects the value of optical band gap. The maximum of the ultraviolet luminescence (UVL) band in ZnO:SiO2:La3+ films is slightly shifted depending on the amount of dopant and is located at λem = 363-367 nm. An increase in UVL intensity was observed upon doping by a factor of 8.4-9.6 compared to ZnO:SiO2 films. A change in the amount of dopant does not lead to sharp changes in the magnitude of the intensity. Thus, the UVL intensity (λex = 260), compared with films with 0.1% La3+ content, varies by 5%-11%. The effect of small amounts of DNA was studied for films doped with La3+. In the case of ZnO:SiO2:La3+, both extinguishing (up to 12%) and ignition (up to 5%) of UVL were observed. Monotone dependencies (which are desirable for the biosensor sensing element) were obtained for samples with La3+ 0.1 and 1.0% content. SEM images show that the images for zinc oxide are white crystallites of different sizes: From 0.5 µm to conglomerates of crystallites-1 µm. In the presence of DNA, the surface structure changes due to the formation of rhomboid structures, whose sizes vary from 3 µm to 35 µm. It is known that lanthanum ions induce the compaction of DNA with the formation of nanoscale structures. © 2020 Astro Ltd

Enhancement of intrinsic protein luminescence in nanosized complex

[No abstract available

Fluorescence Enhancing of 5,10,15,20Tetraphenylporphyrin in Complex with Human Serum Albumin and Gold Nanorods

Using absorption and fluorescence spectroscopy methods we obtained the results demonstrating alterations in spectral characteristics in supramolecular system composed of gold nanorods (AuNR) (10 × 38 nm) and complexes of human serum albumin (HSA) and 5,10,15,20-tetraphenylporphyrin (TPP). TPP fluorescence (λmax = 636 and 658 nm) was found to enhance. The dependence of fluorescence enhancing in time was of nonlinear nature. Maximum TPP fluorescence enhancing value was as high as 16% and it was achieved in 7 min after mixing the components. Simultaneously with TPP fluorescence enhancing we observed a decrease in HSA own fluorescence (λmax = 340 nm) and optical density reduction in maximum of longitudinal localized plasmon band of AuNR (λmax = 752 nm). © 2014, Pleiades Publishing, Inc