7th International conference NBP-2021 “Nanobiophysics: fundamental and applied aspects”

7th International conference “NANOBIOPHYSICS: Fundamental and Applied Aspects” (NBP-2021) took place on October 4-8, 2021 at B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine (Kharkiv, Ukraine). Previous six conferences, starting from 2009, were organized due to joint efforts of B. Verkin Institute for Low Temperature Physics and Engineering of the NAS of Ukraine and Institute of Physics of the NAS of Ukraine on biennial basis in Kharkiv and Kyiv alternatively. Among 80 registered participants from 16 countries about 40 scientists have presented their lectures and posters offline and other participants were joining the sessions online. 16 keynote lectures and 18 oral presentations were made and 51 posters were discussed offline and online. The goal of the conference was achieved: urgent problems, advances and perspectives of the topical scientific direction of nanobiophysics which embraces achievements of modern molecular biophysics and nanotechnology were discussed. The subjects of physical aspects of biomolecular nanosystems, properties of biomolecules on nanoparticles and nanostructured surfaces, nanobiohybrids formation by 1-D or 2-D nanomaterials with bioobjects, theoretical calculations and computer modeling of nanobiosystems, and applied aspects of nanobiophysics were highlighted at the related sessions. Several additional accompanying events were organized in the framework of the conference, including a Round Table “How biophysics and nanosciences meet modern challenges: the case of COVID-19”, a special session of the Ukrainian Biophysical Society, and SPIE (The International Society of Optics and Photonics) and OSA (The Optical Society) Workshop “Career development opportunities for young scientist and students”. Book of abstract based on NBP-2021 materials was published

Non-stationary thermophysical characterization of exfoliated graphite with carbon nanotubes composites

The sheet samples of thermally exfoliated graphite (TEG) carbon nanotubes (CNT) composites (TEG CNT cs) were obtained by persulphate oxidation using chemical (CO) and electrochemical (anode) oxidation (ECAO). Electron microscopy reveals multi layered structures of few layer graphene nanosheets with folded and tubular like fragments.Electron microscopy reveals multilayered structures of few layer graphene nanosheets with folded and tubular like fragments. The effective thermal diffusivity values were estimated by nonstationary photo-pyroelectric thermophysical characterization using the heat pulse and thermo-wave modulation methods. Comparison with other carbon (C) based thermal management materials shows that TEG CNTcs exhibit thermal diffusivity, effusivity and conductivity comparable with those of actual C polymer and C C composites. For TEG CNT cs, evaluated values of phonon mean free path (MFP) and relaxation time (RT) are in the ranges estimated for defective graphene. The values of diffusivity and effusivity, MFP and RT are lower for denser TEG CNT cs obtained by ECAO and are higher for less dense TEG CNT cs obtained by CO. The obtained diffusivity and effusivity values designate TEG CNT cs as suitable thermal management materials.Comment: 33 pages, 5 figure

2D-BN nanoparticles as a spectroscopic marker and drug delivery system with protection properties

An application of 2D-BN nanoparticles as a spectroscopic marker, weak luminescent marker and anticancer drug (doxorubicin, DOX) delivery system with protection properties was studied for the LNCaP strains of cancer cells using FTIR and Raman spectroscopy for analysing the cancer cells, cells with BN, the cancer cells with DOX, and the cancer cells with BN nanoparticles loaded by DOX. Study of IR absorption and Raman spectra of the LNCaP strains of cancer cells incubated with 2D-BN nanoparticles for 1 hour showed that the 2D-BN nanoparticles could pass through the cell membrane and localize inside the membrane or close to the membrane in the cytoplasm of the cells. We registered the spectra of the disturbed lipids during the DOX-2D-BN passing through the membrane. After incubation for 2 hours and more, spectral changes in other structural components of the cell (nuclei, cytoplasm, mitochondria) can be registered. Confocal microscopy showed that a gold nanostructured support enhances the fluorescence of the cancer cells with 2D-BN as well as that with DOX, however the double action of 2D-BN and DOX on the cancer cells aggravates the emission property of the studied system. An MTT test showed that the toxicity of DOX on the 2D-BN nanoparticles is less than that on the reference cells, and at the same time the efficiency of the DOX action on the cancer cells does not change

The enhancement of optical processes near rough surface of metals

Abstract. Last decades the enhancement of optical transitions near metal surface was observed under study the optical processes (luminescence, Raman scattering, IR absorption). The effect consists in an essential increase of the intensity of transition (for example, an effective cross-section increases by factor 10 5 …10 11 for Raman scattering and 10…10 4 for IR absorption) or efficiency of the processes near metal surface (e.g. generation of second harmonic). We have analyzed a various experimental techniques that made it possible to achieve an enhancement in surface enhanced infrared absorption (SEIRA), surface enhanced Raman scattering (SERS), metal-enhanced fluorescence. Under the conditions of our experiment and according to literature data, there was observed enhancement factor which equal to 3…20 for vibrations of various molecular groups in SEIRA. Peculiarity of another optical amplifier, namely, colloidal gold nanoparticles, which were effectively used for enhancement of signal in IR absorption and Raman scattering, metal-enhanced fluorescence, has been studied also. Different roughness of gold surface leads to changes in an enhancement factor. The structural features of bovine serum albumine (BSA) -colloidal gold system and enhancement of guanine that obtained in SEIRA experiment are discussed. Atom force microscopy (AFM) technique was applied to test the roughness of the metal surface. We made an attempt to model the factor of enhancement of electrical field and its frequency dependence for different metal surfaces, and ascertained that silver, gold and copper are the best. Keywords: bovine serum albumin (BSA), Fourier transformed infrared spectroscopy (FTIR), surface enhanced infrared absorption (SEIRA), gold substrate, gold-colloidal nanoparticles, atomic force microscopy (AFM), surface-enhanced Raman scattering (SERS). Manuscript received 08.10.04; accepted for publication 16.12.04