Publications
380 results found
Muginova SV, Vakhranyova ES, Myasnikova DA, et al., 2018, Fluorescence-based Artemisinin Sensing Using a Pyronin B-doped Cellulose Film Reconstituted from Ionic Liquid, ANALYTICAL LETTERS, Vol: 51, Pages: 870-891, ISSN: 0003-2719
Kimber JA, Kazarian SG, 2017, Spectroscopic imaging of biomaterials and biological systems with FTIR microscopy or with quantum cascade lasers, ANALYTICAL AND BIOANALYTICAL CHEMISTRY, Vol: 409, Pages: 5813-5820, ISSN: 1618-2642
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- Citations: 46
Ryu M, Kimber JA, Sato T, et al., 2017, Infrared thermo-spectroscopic imaging of styrene radical polymerization in microfluidics, Chemical Engineering Journal, Vol: 324, Pages: 259-265, ISSN: 1385-8947
A novel infrared (IR) thermo-spectroscopic imaging technique is applied to the simultaneous measurements of IR transmittance spectroscopic images and thermal emission images of heat and mass transfers of styrene monomer polymerization in microfluidics. The heat released is observed in the mixing layer between two laminar flows of styrene monomer and toluene containing an initiator for polymerization. The concentration of chemical species and the independently measured temperature distribution within the mixing layer are determined at the microscale. This is the first report, of such a non-invasive method, to determine both the chemical composition and temperature distribution in microfluidic chemical reactions.
Kharintsev SS, Kharitonov AV, Saikin SK, et al., 2017, Nonlinear Raman effects enhanced by surface plasmon excitation in planar refractory nanoantennas, Nano Letters: a journal dedicated to nanoscience and nanotechnology, Vol: 17, Pages: 5533-5539, ISSN: 1530-6984
We consider a nonlinear mechanism of localized light inelastic scattering within nanopatterned plasmonic and Raman-active titanium nitride (TiN) thin films exposed to continuous-wave (cw) modest-power laser light. Owing to the strong third-order nonlinear interaction between optically excited broadband surface plasmons and localized Stokes and anti-Stokes waves, both stimulated and inverse Raman effects can be observed. We provide experimental evidence for coherent amplification of the localized Raman signals using a planar square-shaped refractory antenna.
Shinzawa H, Turner B, Mizukado J, et al., 2017, Protein hydration in living cells probed by Fourier transform infrared (FT-IR) spectroscopic imaging, ANALYST, Vol: 142, Pages: 2475-2483, ISSN: 0003-2654
Muginova SV, Myasnikova DA, Kazarian SG, et al., 2017, Applications of Ionic Liquids for the Development of Optical Chemical Sensors and Biosensors, ANALYTICAL SCIENCES, Vol: 33, Pages: 261-274, ISSN: 0910-6340
Gabrieli F, Rosi F, Vichi A, et al., 2017, Revealing the Nature and Distribution of Metal Carboxylates in Jackson Pollock's Alchemy (1947) by Micro-Attenuated Total Reflection FT-IR Spectroscopic Imaging, ANALYTICAL CHEMISTRY, Vol: 89, Pages: 1283-1289, ISSN: 0003-2700
Sroka-Bartnicka A, Borkowski L, Ginalska G, et al., 2017, Structural transformation of synthetic hydroxyapatite under simulated <i>in vivo</i> conditions studied with ATR-FTIR spectroscopic imaging, SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, Vol: 171, Pages: 155-161, ISSN: 1386-1425
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- Citations: 46
Martyanov ON, Larichev YV, Morozov EV, et al., 2017, The stability and evolution of oil systems studied via advanced methods in situ, RUSSIAN CHEMICAL REVIEWS, Vol: 86, Pages: 999-1023, ISSN: 0036-021X
Kharintsev SS, Fishman AI, Saikin SK, et al., 2016, Near-field Raman dichroism of azo-polymers exposed to nanoscale dc electrical and optical poling, Nanoscale, Vol: 8, Pages: 19867-19875, ISSN: 2040-3364
Azobenzene-functionalized polymer films are functional materials, where the (planar vs. homeotropic) orientation of azo-dyes can be used for storing data. In order to characterize the nanoscale 3D orientation of the pigments in sub-10 nm thick polymer films we use two complementary techniques: polarization-controlled tip-enhanced Raman scattering (TERS) microscopy and contact scanning capacity microscopy. We demonstrate that the homeotropic and planar orientations of the azo-dyes are produced by applying a local dc electrical field and a resonant longitudinal optical near-field, respectively. For a non-destructive probe of the azo-dye orientation we apply a non-resonant optical near-field and compare the intensities of the Raman-active vibrational modes. We show that near-field Raman dichroism, a characteristic similar to the absorption dichroism used in far-field optics, can be a quantitative indicator of the 3D molecular orientation of the azo-dye at the nanoscale. This study directly benefits the further development of photochromic near-field optical memory that can lead to ultrahigh density information storage.
Trukhan SN, Kazarian SG, Martyanov ON, 2016, Electron Spin Resonance of Slowly Rotating Vanadyls-Effective Tool to Quantify the Sizes of Asphaltenes in Situ, ENERGY & FUELS, Vol: 31, Pages: 387-394, ISSN: 0887-0624
Ewing AV, Kazarian SG, 2016, Infrared spectroscopy and spectroscopic imaging in forensic science, ANALYST, Vol: 142, Pages: 257-272, ISSN: 0003-2654
Shinzawa H, Uchimaru T, Mizukado J, et al., 2016, Non-equilibrium behavior of polyethylene glycol (PEG)/polypropylene glycol (PPG) mixture studied by Fourier transform infrared (FTIR) spectroscopy, Vibrational Spectroscopy, Vol: 88, Pages: 49-55, ISSN: 0924-2031
© 2016 Elsevier B.V. Non-equilibrium behavior of liquid mixture of polyethylene glycol (PEG) and polypropylene glycol (PPG) is studied. During the phase variation of PEG/PPG mixture, time-resolved Fourier transform infrared (FTIR) spectra were collected by attenuated total reflection (ATR) technique to selectively capture the development and subsequent variation of PEG-rich phase, appearing within a layer of the sample adjacent to the measuring surface of the ATR diamond prism. The FTIR spectra were then subjected to a two-dimensional (2D) correlation method to elucidate subtle but important changes in the absorbance of spectral bands. 2D correlation spectra revealed fine details of the non-equilibrium system. During the phase variation, dissociation between PEG and PPG generates free PEG molecules first. The emergence of the free PEG molecules triggers the subsequent self-assembly via the development of intermolecular H-bonding between PEG molecules, which eventually generates bigger PEG aggregates.
Prati S, Milosevic M, Sciutto G, et al., 2016, Analyses of trace amounts of dyes with a new enhanced sensitivity FTIR spectroscopic technique: MU-ATR (metal underlayer ATR spectroscopy)., Analytica Chimica Acta, Vol: 941, Pages: 67-79, ISSN: 1873-4324
The identification of organic dyes is a challenging task in all the fields such as the forensic and conservation sciences, especially in cases where the amount of sample is extremely small. In this paper we propose a new enhanced FTIR method (MU-ATR metal underlayer ATR spectroscopy), which we believe is the first of its kind, for the analysis of a few ng of dyes. With this method, dyed fiber micro-extracts can be analyzed using a commercial FTIR microscope with a fixed incident angle, obtaining the same separation between the different classes of dyes investigated as we obtained analyzing pure dyes in transmission mode. Moreover, the new enhancement method has been validated on a real sample dated back to the 1893, showing how it can be promising for the analysis of trace amounts of organic substances in artistic samples such as dyes in paintings or textiles, varnishes and organic residues on archaeological objects.
Hifumi H, Ewing AV, Kazarian SG, 2016, ATR-FTIR spectroscopic imaging to study the drying and dissolution of pharmaceutical polymer-based films., International Journal of Pharmaceutics, Vol: 515, Pages: 57-68, ISSN: 1873-3476
Pharmaceutical film dosage forms have recently become of interest to pharmaceutical formulation development, particularly for patients who experience difficulty in swallowing tablets or capsules. Furthermore, formulation scientists require a reliable analytical approach to reveal vital insight and investigate the drying process of these films to consolidate suitable quality control. Since most of the polymer-based films containing a drug are produced via solution or dispersion states, an estimation of the physicochemical properties of drugs during drying and dissolution is critical to design novel formulations with the consideration to control drug release, i.e. safety and efficacy to patients. This work presents the novel application of attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopic imaging to study the drying process and dissolution behaviour of polymer-based films. Two types of the ibuprofen containing films, hydroxypropyl methylcellusose (HPMC) based films for immediate release and polyvinylpyrrolidone (PVP) based films for extended release, were studied in modified pH environments and changing hydrophobicity. ATR-FTIR imaging has revealed important information on water ingress into the films and the presence, distribution, and physicochemical state of the drug. ATR-FTIR imaging is a powerful technique to investigate and to deeply understand physicochemical processes for pharmaceutical polymer-based films.
Shinzawa H, Mizukado J, Kazarian SG, 2016, Fourier Transform Infrared (FT-IR) Spectroscopic Imaging Analysis of Partially Miscible PMMA-PEG Blends Using Two-Dimensional Disrelation Mapping., Applied Spectroscopy, ISSN: 1943-3530
A novel technique called disrelation spectroscopic imaging describes the process of identifying an area where a coordinated or out-of-phase change in pattern of spectral absorbance occurs. Disrelation mapping can be viewed as a spatial filter based on the well-established two-dimensional (2D) correlation function to highlight specific areas where disrelated variation occurs between ν1 and ν2 Disrelation intensity develops only if the spectral absorbance measured at ν1 and ν2 vary out of phase with each other within a specific spatial area. The disrelation mapping locates regions where absorbance varies in a dissimilar manner because of the contribution from species of different physical or chemical origins. Consequently, it becomes possible to probe onset of molecular interactions or presence of intermediate forms between components, which is not fully detected by the conventional visualizations based on a single wavenumber. Data analysis using disrelation mapping applied to Fourier transform infrared (FT-IR) spectroscopic images is presented in this study. Data sets of FT-IR spectroscopic images of blends of poly(methyl methacrylate) (PMMA) and polyethylene glycol (PEG) were subjected to the disrelation mapping. It was found that the disrelation intensity between 1730 and 1714 cm(-1) becomes especially acute around the spatial boundary between PMMA and PEG domains within the studied blend sample. Thus the band at 1730 cm(-1) most likely represents the C=O stretching mode of the C=O···H-O species due to the intermolecular hydrogen bonding between PMMA and PEG. The appearance of such disrelation is more noticeable in the PEG-rich region, for the PEG with low molecular weight. Consequently, it suggests that the blends of PMMA and PEG are partially miscible at the molecular level and these intermolecular interactions are affected by the quantity of the terminal -OH groups of the PEG.
Punčochová K, Ewing AV, Gajdošová M, et al., 2016, The combined use of imaging approaches to assess drug release from multicomponent solid dispersions, Pharmaceutical Research, Vol: 34, Pages: 990-1001, ISSN: 1573-904X
PURPOSE: Imaging methods were used as tools to provide an understanding of phenomena that occur during dissolution experiments, and ultimately to select the best ratio of two polymers in a matrix in terms of enhancement of the dissolution rate and prevention of crystallization during dissolution. METHODS: Magnetic resonance imaging, ATR-FTIR spectroscopic imaging and Raman mapping have been used to study the release mechanism of a poorly water soluble drug, aprepitant, from multicomponent amorphous solid dispersions. Solid dispersions were prepared based on the combination of two selected polymers - Soluplus, as a solubilizer, and PVP, as a dissolution enhancer. Formulations were prepared in a ratio of Soluplus:PVP 1:10, 1:5, 1:3, and 1:1, in order to obtain favorable properties of the polymer carrier. RESULTS: The crystallization of aprepitant during dissolution has occurred to a varying degree in the polymer ratios 1:10, 1:5, and 1:3, but the increasing presence of Soluplus in the formulation delayed the onset of crystallization. The Soluplus:PVP 1:1 solid dispersion proved to be the best matrix studied, combining the abilities of both polymers in a synergistic manner. CONCLUSIONS: Aprepitant dissolution rate has been significantly enhanced. This study highlights the benefits of combining imaging methods in order to understand the release process.
Boulet-Audet M, Kazarian SG, Byrne B, 2016, In-column ATR-FTIR spectroscopy to monitor affinity chromatography purification of monoclonal antibodies, Scientific Reports, Vol: 6, ISSN: 2045-2322
In recent years many monoclonal antibodies (mAb) have entered the biotherapeutics market, offering new treatments for chronic and life-threatening diseases. Protein A resin captures monoclonal antibody (mAb) effectively, but the binding capacity decays over repeated purification cycles. On an industrial scale, replacing fouled Protein A affinity chromatography resin accounts for a large proportion of the raw material cost. Cleaning-in-place (CIP) procedures were developed to extend Protein A resin lifespan, but chromatograms cannot reliably quantify any remaining contaminants over repeated cycles. To study resin fouling in situ, we coupled affinity chromatography and Fourier transform infrared (FTIR) spectroscopy for the first time by embedding an attenuated total reflection (ATR) sensor inside a micro-scale column while measuring the UV 280 nm and conductivity. Our approach quantified the in-column protein concentration in the resin bed and determined protein conformation. Our results showed that Protein A ligand leached during CIP. We also found that host cell proteins bound to the Protein A resin even more strongly than mAbs and that typical CIP conditions do not remove all fouling contaminants. The insights derived from in-column ATR-FTIR spectroscopy monitoring could contribute to mAb purification quality assurance as well as guide the development of more effective CIP conditions to optimise resin lifespan.
Muginova SV, Myasnikova DA, Kazarian SG, et al., 2016, Evaluation of novel applications of cellulose hydrogel films reconstituted from acetate and chloride of 1-butyl-3-methylimidazolium by comparing their optical, mechanical, and adsorption properties, Materials Today Communications, Vol: 8, Pages: 108-117, ISSN: 2352-4928
To evaluate new applications of cellulose hydrogel films prepared via the dissolution-regeneration of microcrystalline cellulose in two hydrophilic ionic liquids – 1-butyl-3-methylimidazolium acetate (BmimAc) and chloride (BmimCl), their optical, mechanical, and adsorption properties were concurrently studied and compared for the first time. The mild conditions under which both films were optically transparent and easy to handle were found. The BmimAc-reconstituted films exhibited an increased tensile strength and elongation at break of 9.5 and 2.5 times, respectively, than the BmimCl-reconstituted films. Due to the sponge-like morphology of the surface, BmimAc-reconstituted films demonstrate enhanced adsorption ability with respect to indigo carmine that is widely applied for industrial needs. This finding opens up opportunities for their use as an adsorbent for dyes. BmimCl-reconstituted films appeared to be a more promising material for the noncovalent immobilization of pyronin B, which is a component of the optical indicator systems for detecting different biologically active compounds.
Goodacre R, Baker MJ, Graham D, et al., 2016, Biofluids and other techniques: general discussion., Faraday Discuss, Vol: 187, Pages: 575-601
Goodacre R, Sergo V, Barr H, et al., 2016, Clinical Spectroscopy: general discussion, Faraday Discussions, Vol: 187, Pages: 429-460, ISSN: 1364-5498
Baker MJ, Goodacre R, Sammon C, et al., 2016, Single cell analysis/data handling: general discussion., Faraday Discuss, Vol: 187, Pages: 299-327
Sammon C, Schultz ZD, Kazarian S, et al., 2016, Spectral Pathology: general discussion., Faraday Discuss, Vol: 187, Pages: 155-186
Gabrienko AA, Martyanov ON, Kazarian SG, 2016, Behavior of Asphaltenes in Crude Oil at High-Pressure CO2 Conditions: In Situ Attenuated Total Reflection-Fourier Transform Infrared Spectroscopic Imaging Study, Energy & Fuels, Vol: 30, Pages: 4750-4757, ISSN: 1520-5029
Taylor JD, Hawthorne WJ, Lo J, et al., 2016, Electrostatically-guided inhibition of Curli amyloid nucleation by the CsgC-like family of chaperones, Scientific Reports, Vol: 6, ISSN: 2045-2322
Polypeptide aggregation into amyloid is linked with several debilitating human diseases.Despite the inherent risk of aggregation-induced cytotoxicity, bacteria control the export ofamyloid-prone subunits and assemble adhesive amyloid fibres during biofilm formation. AnEscherichia protein, CsgC potently inhibits amyloid formation of curli amyloid proteins.Here we unlock its mechanism of action, and show that CsgC strongly inhibits primarynucleation via electrostatically-guided molecular encounters, which expands theconformational distribution of disordered curli subunits. This delays the formation of higherorder intermediates and maintains amyloidogenic subunits in a secretion-competent form.New structural insight also reveal that CsgC is part of diverse family of bacterial amyloidinhibitors. Curli assembly is therefore not only arrested in the periplasm, but the preservationof conformational flexibility also enables efficient secretion to the cellsurface. Understanding how bacteria safely handle amyloidogenic polypeptides contributetowards efforts to control aggregation in disease-causing amyloids and amyloid-based biotechnological applications.
Ewing AV, Clarke GS, Kazarian SG, 2016, Attenuated total reflection-Fourier transform infrared spectroscopic imaging of pharmaceuticals in microfluidic devices, Biomicrofluidics, Vol: 10, Pages: 024125-1-024125-13, ISSN: 1932-1058
The poor aqueous solubility of many active pharmaceutical ingredients presents challenges for effective drug delivery. In this study, the combination of attenuated total reflection (ATR)-FTIR spectroscopic imaging with specifically designed polydimethylsiloxane microfluidic devices to study drug release from pharmaceutical formulations has been developed. First, the high-throughput analysis of the dissolution of micro-formulations studied under flowing conditions has been introduced using a model formulation of ibuprofen and polyethylene glycol. The behaviour and release of the drug was monitored in situ under different pH conditions. In contrast to the neutral solution, where both the drug and excipient dissolved at a similar rate, structural change from the molecularly dispersed to a crystalline form of ibuprofen was characterised in the obtained spectroscopic images and the corresponding ATR-FTIR spectra for the experiments carried out in the acidic medium. Further investigations into the behaviour of the drug after its release from formulations (i.e., dissolved drug) were also undertaken. Different solutions of sodium ibuprofen dissolved in a neutral medium were studied upon contact with acidic conditions. The phase transition from a dissolved species of sodium ibuprofen to the formation of solid crystalline ibuprofen was revealed in the microfluidic channels. This innovative approach could offer a promising platform for high-throughput analysis of a range of micro-formulations, which are of current interest due to the advent of 3D printed pharmaceutical and microparticulate delivery systems. Furthermore, the ability to study dissolved drug in solution under flowing conditions can be useful for the studies of the diffusion of drugs into tissues or live cells.
Kimber JA, Foreman L, Turner B, et al., 2016, FTIR spectroscopic imaging and mapping with correcting lenses for studies of biological cells and tissues, Faraday Discussions, Vol: 187, Pages: 69-85, ISSN: 1364-5498
Histopathology of tissue samples is used to determine the progression of cancer usually by staining and visual analysis. It is recognised that disease progression from healthy tissue to cancerous is accompanied by spectral signature changes in the mid-infrared range. In this work, FTIR spectroscopic imaging in transmission mode using a focal plane array (96 × 96 pixels) has been applied to the characterisation of Barrett's oesophageal adenocarcinoma. To correct optical aberrations, infrared transparent lenses were used of the same material (CaF2) as the slide on which biopsies were fixed. The lenses acted as an immersion objective, reducing scattering and improving spatial resolution. A novel mapping approach using a sliding lens is presented where spectral images obtained with added lenses are stitched together such that the dataset contained a representative section of the oesophageal tissue. Images were also acquired in transmission mode using high-magnification optics for enhanced spatial resolution, as well as with a germanium micro-ATR objective. The reduction of scattering was assessed using k-means clustering. The same tissue section map, which contained a region of high grade dysplasia, was analysed using hierarchical clustering analysis. A reduction of the trough at 1077 cm−1 in the second derivative spectra was identified as an indicator of high grade dysplasia. In addition, the spatial resolution obtained with the lens using high-magnification optics was assessed by measurements of a sharp interface of polymer laminate, which was also compared with that achieved with micro ATR-FTIR imaging. In transmission mode using the lens, it was determined to be 8.5 μm and using micro-ATR imaging, the resolution was 3 μm for the band at a wavelength of ca. 3 μm. The spatial resolution was also assessed with and without the added lens, in normal and high-magnification modes using a USAF target. Spectroscopic images of cells in transmission mode u
Gabrienko AA, Ewing AV, Chibiryaev AM, et al., 2016, New insights into the mechanism of interaction between CO<sub>2</sub> and polymers from thermodynamic parameters obtained by <i>in</i> <i>situ</i> ATR-FTIR spectroscopy, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 18, Pages: 6465-6475, ISSN: 1463-9076
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- Citations: 38
Kazarian SG, Chan KLA, 2016, FTIR IMAGING OF POLYMERIC MATERIALS, POLYMER MORPHOLOGY: PRINCIPLES, CHARACTERIZATION, AND PROCESSING, Editors: Guo, Publisher: JOHN WILEY & SONS INC, Pages: 118-130, ISBN: 978-1-118-45215-8
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- Citations: 4
Ewing AV, Biggart GD, Hale CR, et al., 2015, Comparison of pharmaceutical formulations: ATR-FTIR spectroscopic imaging to study drug-carrier interactions, INTERNATIONAL JOURNAL OF PHARMACEUTICS, Vol: 495, Pages: 112-121, ISSN: 0378-5173
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- Citations: 22
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