Valdas SablinskasVilnius University · Institute of Chemical Physics
Valdas Sablinskas
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164
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Introduction
Valdas Sablinskas currently works at the Institute of Chemical Physics, Vilnius University. Valdas does research in Biophysics. Their current projects are 'Cluster structure of hydrogen-bonded liquids' and "Stop fake food".
Skills and Expertise
Publications
Publications (164)
Matrix isolation infrared absorption spectroscopy was combined with quantum chemical calculations to characterize valeric acid conformers. Geometries and vibrational spectra of possible valeric acid conformers were calculated using MP2 and B3LYP levels of theory. MP2 calculations predict that the most stable form of valeric acid is a nonlinear alip...
We investigated the formation of graphite nanocrystals covered with graphite oxide for white light generation. The nanoparticles were formed using cost-efficient oxidation of a carbon-based dye pigment at different temperatures and verified using X-ray diffraction and Raman measurements. Formation of the graphite nanoparticles via thermal annealing...
Extending applications of Ti3C2Tx MXene in nanocomposites and across fields of electronics, energy storage, energy conversion, and sensor technologies necessitates simple and efficient analytical methods. Raman spectroscopy is a critical tool for assessing MXene composites; however, high laser powers and temperatures can lead to the materials’ dete...
Objective: Our study aimed to evaluate the success rate of ESWL and identify relevant treatment-specific factors affecting treatment outcomes, as well as to assess the accuracy of the updated Triple D scoring system and compare it with older systems. Material and Methods: A prospective study of 71 patients who received ESWL treatment for renal ston...
Magneto-plasmonic nanoparticles were fabricated using a 1064 nm picosecond-pulsed laser for ablation of Fe/Au and Fe/Au/Fe composite thin films in acetone. Nanoparticles were characterized by electron microscopy, ultraviolet-visible (UV-VIS) absorption, and Raman spectroscopy. Hybrid nanoparticles were arranged on an aluminum substrate by a magneti...
Significance:
Pancreatic surgery is a highly demanding and routinely applied procedure for the treatment of several pancreatic lesions. The outcome of patients with malignant entities crucially depends on the margin resection status of the tumor. Frozen section analysis for intraoperative evaluation of tissue is still time consuming and laborious....
Surgical treatment is widely applied curative approach for bladder cancer. White light cystoscopy (WLC) is currently used for intraoperative diagnostics of malignant lesions but has relatively high false-negative rate. Here we represent an application of label free fiber-based attenuated total reflection infrared spectroscopy (ATR IR) for freshly r...
Background
The introduction of the holmium laser for lithotripsy and minimally invasive techniques in endoscopy increased the popularity of stone dusting techniques. Retrieving stone pieces for an analysis increases the economic burden of surgery and operative time. Novel methods are needed for the analysis of convenient urolithiasis composition....
1-chloromethyl-1-fluorosilacyclopentane (1-ClM-1-FSiCP) was synthesized for the first time and investigated by means of vibrational spectroscopy and theoretical calculations. FT-IR and Raman spectroscopic methods were implemented to collect vibrational spectra of 1-ClM-1-FSiCP. The conformational analysis was performed utilizing FT-IR matrix isolat...
Vibrational spectroscopy provides the possibility for sensitive and precise detection of chemical changes in biomolecules due to development of cancers. In this work, label-free near-infrared surface enhanced Raman spectroscopy (SERS) was applied for the differentiation between cancerous and normal human bladder tissues via analysis of the extracel...
The widespread use of plastic without the sustainable management of the plastic waste has led to its accumulation in the environment. The presence of microplastics even in drinking water and food products is of immense concern. This situation is getting even more complicated due to the limited knowledge about the sources of microplastics and their...
Keywords: multi-walled carbon nanotubes (MWCNT), iridium-doped, nanohybrid composite, Raman spectrum, energy-dispersive X-ray spectroscopy Multi-walled carbon nanotubes have been prepared by chemical vapour deposition pyrolysis of ethyl alcohol at 665°C. The addition of atoms other than carbon to the nanostructure, in our case the iridium component...
1-chloro-1-chloromethylsilacyclohexane (1-Cl-1-ClMSiCH) is a newly synthesized molecular compound whose conformational analysis was performed by means of vibrational spectroscopy and theoretical calculations. Conventional ATR-FTIR and Raman spectroscopic methods were used to obtain vibrational spectra of the liquid sample. Additionally, FTIR spectr...
Urolithiasis is a common disease worldwide, but its causes are still not well understood. In many cases, crystalluria provides an early indication of urinary stone formation, and characterisation of the urinary deposits could help doctors to take early preventative measures to stop their further growth. Nowadays, the gold standard for the analysis...
In this research, we have demonstrated that 2D Ti3C2Xn-based MXene (MXene) films are suitable for the design of surface-enhanced Raman spectroscopy (SERS)-based sensors. The enhanced SERS signal was observed for a salicylic acid molecule on Ti3C2Tx-based MXene film. Confirmation of the adsorption of the salicylic acid molecule and the formation of...
The goal of this study is development of ultra-sensitive and reproducible SERS platform based on novel magnetoplasmonic nanoparticles produced by laser ablation. The magnetic part of hybrid nanoparticles ensures manipulation of the nanoparticles by magnetic field by arranging them at biological surfaces in a special geometry resulting in high and r...
This work presents the application of EC-SERS spectroscopy for the detection of caffeine consumption from human saliva. Caffeine and paraxanthine as the major metabolite of caffeine were tested. Model samples of saliva spiked with caffeine were investigated, and detection of caffeine in real-life saliva samples was tested in order to ensure the via...
In this contribution, more evidence is provided to support the presence of low-temperature anomaly in CsPbBr 3 single crystals.
Pathogenic strains of bacteria are causing various illnesses all around the world and have a major socio‐economic impact. Thus, fast and low‐cost methods for the microbial control of foods are needed. One of them might be photosensitization. This study looks deeper into the mechanism of E. coli damage by Chlorophyllin‐based photosensitization.
Fluo...
Cesium–lead–bromide (CsPbBr3) is the simplest all inorganic halide perovskite. It serves as a reference material for understanding the exceptional solar cell properties of the organic–inorganic hybrid halide perovskites and is itself discussed as an alternative absorber material. Broadband dielectric spectroscopy has proven to yield an in depth und...
Since 1-chloromethyl-1-fluorosilacyclohexane is a newly synthesized molecular compound its structural parameters and conformational stability is unknown. Raman and infrared vibrational spectroscopy methods were employed for analysis of this molecule. IR spectra were recorded for both gas phase and liquid sample, whereas the Raman experiments were p...
We present the infrared spectroscopy study of three types of human healthy and cancerous tissues using standard ATR and fiber optics based ATR techniques. The use of fiber based ATR probes eliminates the need to bring the sample under the study to the spectroscopic instrument and opens the path for the application of infrared spectroscopy for the s...
Tetrahydrofuran (THF) is a widely used chemical compound, in particular as a solvent in organic and inorganic synthesis. The THF molecule has also an interesting property, namely, undergoes pseudorotation, similar to the case of the cyclopentane. Low energy difference between the envelope (Cs symmetry) and twisted (C2 symmetry) conformations of the...
More than 90% of solid kidney tumors are cancerous and have to be treated by surgical resection where surgical outcomes and patient prognosis are dependent on the tumor discrimination. The development of alternative approaches based on a new generation of fiber attenuated total reflection (ATR) probes could aid tumor identification even under intra...
Aspirin being freely available as an over the counter drug has a high overdose risk and can cause severe health symptoms. The methods used in clinics for the detection of such drugs (pharmaceuticals) in bodily fluids are mostly based on liquid chromatography and mass spectroscopy. These methods are known to be precise; however, they both require lo...
The structure of trifluoroacetylacetone in argon and nitrogen matrices and association with water molecules were studied by the means of Fourier transform infrared absorption spectroscopy (FTIR) aided with density functional theory (DFT) calculations. The absorption bands of trifluoroacetylacetone isolated in argon can be attributed to the single c...
Different configurations of (H5O2)⁺− Ar, (H5O2)⁺− Ne and (H5O2)⁺− He complexes were calculated using DFT methods and series of Dunning and Pople basis sets. The possibility of the existence of an equilibrium configuration with C2 symmetry for complexes analyzed was in focus of the studies carried out. DFT methods that do not take into account dispe...
Effects of the dispersion interactions on the parameters of the water dimer equilibrium configuration and IR spectra are analyzed in the paper. Dimer equilibrium geometry was calculated using a series of the density functionals, both with (B3LYP-D3, B2PLYPD, B2PLYP-D3, mPW2PLYPD, wB97XD) and without (B3LYP, B2PLYP, mPW2PLYP, wB97X) accounting of th...
Polymer composite materials are used increasingly in material and engineering science. They provide outstanding mechanical and optical properties. The linkage between the polymer materials is crucial for achieving the desired properties. Understanding the linkage and structure of the polymer-polymer interface layer is a key for utilization polymer...
Association of acetylacetone molecules with water was studied by means of infrared absorption spectroscopy aided by matrix isolation technique. The spectra of acetylacetone–water mixtures isolated in low temperature argon and nitrogen matrices revealed additional spectral bands, not observed in the spectra of pure substances, thus confirming the fo...
Raman spectra of liquid water and ice were measured at different temperatures. The intensity of the band assigned to bending vibrations of water molecules was observed to decrease at the liquid-to-solid transition, while the Raman line near 2200cm-1showed an anomalously high intensity in the solid phase. A tetrahedral model was used for computer an...
Herein, a technique to analyze air-dried kidney tissue impression smears by means of Attenuated Total Reflection Infrared (ATR-IR) spectroscopy is presented. Spectral tumor markers - absorption bands of glycogen - are identified in the ATR-IR spectra of the kidney tissue smear samples. Thin kidney tissue cryo-sections currently used for IR spectros...
We present a novel approach for detection of cancerous kidney tissue areas by measuring surface enhanced Raman scattering (SERS) spectra of extracellular fluid taken from kidney tissue. The method is based on spectral analysis of the cancerous and normal tissue areas in order to find the specific spectral markers. The samples were prepared by slidi...
The frequencies and intensities of vibration–rotational transitions of water molecules in an argon matrix were calculated for temperatures of 6 and 30 K. The rigid asymmetric top approximation was used with available literature values of the effective rotational constants in the ground and excited vibrational states. The calculations were carried o...
Surface enhanced Raman scattering (SERS) spectroscopy is a useful method for detection of trace amounts of molecules. It has already been successfully implemented for detection of explosives, food additives, biomarkers in blood or urine, etc. In the last decade, SERS spectroscopy was introduced into the field of health sciences and has been especia...
The structure and harmonic- and anharmonic IR spectra of the protonated water dimer (PWD) were calculated in C1, C2 and CS symmetry at the MP4/acc-pVTZ level of theory. We found that structure and IR spectra are practically identical in C2 and C1 symmetry demonstrating that an equilibrium С1 configuration of the PWD is not realized. Anharmonic coup...
A new mechanism for combinatorial broadening of donor-OH stretching-vibration absorption bands in molecular clusters with H-bonds is proposed. It enables the experimentally observed increase of the O–H stretching-vibration bandwidth with increasing number of molecules in H-bonded clusters to be explained. Knowledge of the half-width of the OH stret...
Tracing aetiology and pathogenesis of urinary stone disease is of great importance in order to prescribe appropriate treatment and prevent recurrences. For this purpose, morphological examination combined with determination of chemical composition of urinary stones is fundamental. In this work, we have evaluated the potential of multimodal nonlinea...
Uric acid concentration in human bodily fluids is an important marker for disorders such as gout, pre-eclamsia or cardiovascular disease. However, currently used methods for its detection either lack sensitivity or require sophisticated, bulky and expensive equipment. In this work, we show that by using surface-enhanced Raman scattering spectroscop...
Determination of cancerous and normal kidney tissues during partial, simple or radical nephrectomy surgery was performed by using differences in the IR absorption spectra of extracellular fluid taken from the corresponding tissue areas. The samples were prepared by stamping of the kidney tissue on ATR diamond crystal. The spectral measurements were...
FTIR spectra of monohydric alcohols 1-nonanol (C9H19OH) and 1-decanol (C10H21OH) were registered in the spectral region from 500 cm-1 to 4000 cm-1 at temperatures from -50 to + 25 {\deg}C for 1-nonanol and +100 {\deg}C for 1-decanol. Temperature-induced spectra changes were compared for these two alcohols. The authors link the observed changes with...
H&E stained sections of SCI in rat models with and without alginate hydrogel implant at one and six months after injury.
(JPG)
Analysis of the contralateral nervous tissue.
IR spectroscopic images of SCI in rat models with and without alginate hydrogel implant at one and six months after injury, obtained plotting the intensity of the lipid-related band at 1735 cm-1.
(JPG)
Analysis of the fibrotic lesion.
IR spectroscopic images of SCI in rat models with and without alginate hydrogel implant at one and six months after injury, obtained plotting the intensity of the collagen-related band at 1242 cm-1.
(JPG)
Matrix isolation method allows investigating individual molecules and clusters. Basing on the registered spectra, one can obtain the information on cluster structures in n-hexanol and the changing of these structures during phase transitions. Using quantum chemical methods, the energy of hydrogen bonds for clusters of different sizes and their spat...
Molecular vibrational spectra of methanol in argon and nitrogen matrices have been studied. Since methanol belongs to a class of substances with hydrogen bonds, there is a possibility of forming molecular associations and clusters with various numbers of molecules. IR spectra of methanol in Ar and N2 matrices experimentally obtained in the temperat...
Spinal cord injury (SCI) induces complex biochemical changes, which result in inhibition of nervous tissue regeneration abilities. In this study, Fourier-transform infrared (FT-IR) spectroscopy was applied to assess the outcomes of implants made of a novel type of non-functionalized soft calcium alginate hydrogel in a rat model of spinal cord hemis...
Raman spectra of liquid, and infrared spectra of gaseous as well as matrix isolated 1,1,2,2-tetrachloro-1,3-disilacyclopentane were recorded and analyzed with the aid of DFT calculations. Complete assignment of the experimental vibrational spectral bands is made. Experimental results and DFT calculations confirm that 1,1,2,2-tetrachloro-1,3-disilac...
Molecular vibrational spectra of methanol in argon and nitrogen matrices have been studied. Since methanol belongs to a class of substances with hydrogen bonds, there is a possibility of forming molecular associations and clusters with various numbers of molecules. IR spectra of methanol in Ar and N2 matrices experimentally obtained in the temperat...
Raman spectroscopy is known to provide information about the quality of the single walled carbon nanotubes (SWCNT). The information is based on the intensity ratio of D and G spectral modes and the frequency of RBM modes. However due to resonance nature of Raman spectrum of the nanotubes this method is not suitable to detect functionalization of th...
Alcohol molecules can form hydrogen bonds and arrange in different structures named clusters. The aim of this work is to study the behavior of a cluster structure of alcohols at phase transitions and to elucidate the structure of clusters in the solid and liquid states. The objects of investigation are monohydric alcohols n-pentanol (CH2)4CH3–OH an...
We present a novel approach to the detection of cancerous kidney tissue areas by measuring vibrational spectra (IR absorption or SERS) of intercellular fluid taken from the tissue. The method is based on spectral analysis of cancerous and normal tissue areas in order to find specific spectral markers. The samples were prepared by sliding the kidney...
The structure and IR absorption spectrum of the formic acid dimer (FAD) were calculated using the B3LYP DFT functional and cc-pVTZ basis set. Matrices of force and anharmonic constants were calculated in order to find the fundamental frequencies more accurately. The 1D and 2D potential energy surfaces (PES) were built using symmetry coordinates and...
Raman spectra of germacyclohexane in liquid and solid states were recorded and depolarization data obtained. Infrared absorption spectra of the vapor and liquid have been studied. The wavenumbers of the vibrational modes were derived in the harmonic and anharmonic approximation in B3LYP/ccpVTZ calculations. According to the calculations, germacyclo...
IR and Raman spectra of the malonaldehyde molecule and its deuterated analogues were calculated in the B3LYP/cc-pVQZ approximation. Anharmonicity effects were taken into account both in the context of a standard model of the second order perturbation theory and by constructing the potential energy surfaces (PES) with a limited number of dimensions...
Infrared spectra of gaseous, liquid and matrix isolated samples of newly synthesized 1,1-dimethyl-2-oxy-1-silacyclohexane were recorded. Raman spectra of 1,1-dimethyl-2-oxy-1-silacyclohexane in liquid and solid states were obtained in the temperature range from 170 to 340 K. Ab initio HF and DFT B3LYP calculations were performed in order to determi...
FTIR
spectra of 1-propanol in an argon matrix were studied in the range 11–30 K. Principal component analysis of dynamic FTIR
spectra and nonlinear band shape fitting has been carried out. The peaks of monomer, open dimer, mixed propanol-water dimer and those of higher H-bond clusters have been resolved and analyzed. The attribution of certain FTIR...
The aim of the study was to investigate the prevalence of metabolic syndrome in patients with uric acid and calcium–based kidney stones and to investigate the relationship between metabolic syndrome and type of kidney stone using infrared spectroscopy to evaluate the chemical composition of kidney stones Sixty patients with urolithiasis were examin...