Aneta Kowalska - Academia.edu (original) (raw)
Papers by Aneta Kowalska
Journal of Molecular Structure, Jul 1, 2006
The films of (BEDT-TTF) 2 XF 6 (where XZP, Sb) and (BEDT-TTF)[Ni(dmit) 2 ] 2 were electrodeposite... more The films of (BEDT-TTF) 2 XF 6 (where XZP, Sb) and (BEDT-TTF)[Ni(dmit) 2 ] 2 were electrodeposited on an intrinsic Si(001) electrode. All samples are examined by scanning electron microscopy, X-ray diffraction data and Raman spectra. The results evidence that new (BEDT-TTF) 2 SbF 6 and (BEDT-TTF)[Ni(dmit) 2 ] 2 phases (compared to those obtained on a common Pt wire) are grown on the silicon electrode.
Analytical Methods, 2016
, 1. SERS substrate characteristic. In order to examine the SERS activity of the (AgNPs/FTO) subs... more , 1. SERS substrate characteristic. In order to examine the SERS activity of the (AgNPs/FTO) substrate, the enhancement factor (EF) was calculated for p-MBA as a standard analyte. The AgNPs/FTO substrate was incubated in 1.0 × 10-6 M p-MBA solution in ethanol for 60 min and then washed with deionized water. The surface enhancement factor (EF) for p-MBA was calculated according to the following equation: Electronic Supplementary Material (ESI) for Analytical Methods.
Analytical Methods, 2016
The article presents surface enhanced Raman scattering (SERS) technique associated with the princ... more The article presents surface enhanced Raman scattering (SERS) technique associated with the principal component analysis (PCA) as a fast and reliable method for the study of interactions between the A, B, AB and O (abr. ABO) blood groups antigen and complementary monoclonal A and B antibodies. The possibility of simultaneous detection and differentiation within the ABO group was evaluated. Using 785 nm excitation wavelength, distinctive spectral changes among all types of the studied blood groups were found for mixtures of red blood cells (RBCs) with the A or B antibody. For PCA analysis, all the spectral data were divided into two main groups based on the type of antibody. The obtained PC scores in the area of antigen-antibody interactions (1311-1345 cm À1) allow differentiation within blood groups with accuracy from 96% to 98%. Additionally, for this region the characteristic marker bands of specific antigen-antibody interactions in relation to both ABO system and antibody were established. The results show excellent segregation of the obtained data and the possibility to use SERS for determination of ABO blood group. Our study proves that SERS is one of the most sensitive techniques for investigations of biological samples and may be used as a new tool that provides one-step comprehensive and reliable medical diagnosis.
Analytical and Bioanalytical Chemistry, Jun 16, 2018
One of the potential applications of surface-enhanced Raman spectroscopy (SERS) is the detection ... more One of the potential applications of surface-enhanced Raman spectroscopy (SERS) is the detection of biological compounds and microorganisms. Here we demonstrate that SERS coupled with principal component analysis (PCA) serves as a perfect method for determining the taxonomic affiliation of bacteria at the strain level. We demonstrate for the first time that it is possible to distinguish different genoserogroups within a single species, Listeria monocytogenes, which is one of the most virulent foodborne pathogens and in some cases contact with which may be fatal. We also postulate that it is possible to detect additional proteins in the L. monocytogenes cell envelope, which provide resistance to benzalkonium chloride and cadmium. A better understanding of this infectious agent could help in selecting the appropriate pharmaceutical product for enhanced treatment.
Journal of Raman Spectroscopy, Jul 27, 2021
We present herein a label-free method based on surface-enhanced Raman spectroscopy (SERS) that wa... more We present herein a label-free method based on surface-enhanced Raman spectroscopy (SERS) that was performed using a silicon-based SERS platform. The differentiation between primary and secondary brain tumors SERS data was completed partial least squares (PLS) method with a very high 85% of accuracy (in only first and second factors), whereas calculated using principal component analysis (PCA) method gives 74% (in two consecutive components). Additionally, due to the fact that the interleukin-10 (IL-10) cytokine receptor may act in cancer as both an immunosuppressive and an immunostimulant factor, the correlation between the tumor grading and the cytokine receptor are presented. Obtained data indicate that the function of IL-10 cytokine receptor subunit alpha most probably depends or is closely related to the tumor stage. K E Y W O R D S brain tumors, cytokine, interleukin-10, multivariate analysis, silicon-based SERS platform, surface-enhanced Raman spectroscopy Highlights • The correlations between the brain tumor grading and their IL-10 cytokine receptor level are presented. • Surface-enhanced Raman spectroscopy and the partial least squares regression was applied as methods of differentiations between primary and secondary brain tumors. • The presented protocol of homogenates tissues analysis may open the way for the new cancer therapy. • Presented method of tumor differentiation may improve the diagnostic accuracy.
Synthetic Metals, Apr 1, 2010
The new-(BEDT-TTF) 2 SbF 6 phase was grown by electrodeposition on a Si(0 0 1) electrode. This ne... more The new-(BEDT-TTF) 2 SbF 6 phase was grown by electrodeposition on a Si(0 0 1) electrode. This new phase was characterized by X-ray diffraction (XRD) and electronic conductivity measurements, accompanied by calculations of electronic band structures and Fermi surfaces. Below T = 120 K, a decrease in the electronic conductivity suggests a phase transition, attributed to anion ordering.
Social Science Research Network, 2023
Physica B-condensed Matter, Jun 1, 2012
ABSTRACT A strong electron–phonon coupling effect, referred to as electron–molecular vibration (e... more ABSTRACT A strong electron–phonon coupling effect, referred to as electron–molecular vibration (e–mv) coupling, induces characteristic vibronic signals in the vibrational spectra of organic conductors. This paper discusses a new spectroscopic signal induced by the e–mv coupling effect, and the physical implications of its emergence. This vibronic signal, attributable to an overtone of a molecular vibration, appears with an anti-resonance form in the infrared spectrum of some mixed-valency complexes when the compounds undergo a charge-ordering transition. Based on the results of cluster model calculations, the activation of the overtone signal is interpreted as an indication of the generation of anharmonicity in the electronic potential. This analysis suggests that the series of the complexes should possess potential nonlinear optical abilities, though these compounds have long been viewed as electric conductors having the opposite characteristics of dielectrics that show nonlinear optical properties.
Beilstein Journal of Organic Chemistry, Oct 25, 2017
The complexation of the antifolate pemetrexed (PTX) with native cyclodextrins was studied. This p... more The complexation of the antifolate pemetrexed (PTX) with native cyclodextrins was studied. This process, along with the findings gathered for the structurally related folic acid was treated as a model for exploiting host-guest interactions of this class of guest molecules in the gas phase, in solution and in the solid state. Mass spectrometry was employed for the investigation of the architecture and relative gas-phase stabilities of these supramolecular complexes. The mode of complexation was further tracked by 1D and 2D NMR proving the formation of the exclusion-type complex with α-CD and pseudorotaxane inclusion-type complexes with β-, and γ-CDs. UV-vis titrations at pH 7.4 gave association constants for the obtained complexes. The stability of the complexes increases in the series: α-CD/PTX < γ-CD/PTX << β-CD/PTX. The association of PTX with a monomer cyclodextrin equivalentmethyl α-D-glucopyranoside-was investigated for a deeper understanding of the type of host-guest interactions. Solid state studies of PTX/CDs were performed using FTIR-ATR and Raman spectroscopy techniques.
Physica B-condensed Matter, Jun 1, 2010
ABSTRACT This paper reports the observation of optical second-harmonic generation (SHG) in an org... more ABSTRACT This paper reports the observation of optical second-harmonic generation (SHG) in an organic conductor α′-(BEDT-TTF)2IBr2. The charge-transfer complex undergoes a semiconductor-to-semiconductor transition around 200K due to charge ordering. Activation of SHG manifested that the complex generates ferroelectric polarization in the charge ordered phase. The observation of the image of SHG revealed that the nonlinear optical signal was generated from limited regions of the single crystal. The inhomogeneous distribution of SHG signal is discussed in terms of the possible competition of ferroelectric and non-polar phases in the phase diagram of the compound.
Journal of Raman Spectroscopy, Mar 8, 2015
Novel surface enhanced Raman spectroscopy (SERS) platforms have been prepared and used for the ba... more Novel surface enhanced Raman spectroscopy (SERS) platforms have been prepared and used for the bacteria detection. Unlike typical, expensive SERS platforms prepared from gold or silver, the presented platforms are prepared using copper. A new, simple, cost-efficient and fast high pressure method is used for platform fabrication, through the decomposition of copper hydride. The platform enhancement factors are verified using the malachite green isothiocyanate as a standard. The platforms exhibit extremely high SERS enhancement factors depending on pressure used for their preparation. The calculated enhancement factors have been found in the range between 1.5 × 10 6 and 4.6 × 10 7. The SERS spectra reproducibility is established both across a single platform and among different platforms. The average spectral correlation coefficient (Γ) has been calculated to be 0.82. Fully characterized SERS platforms have then been used for detecting Staphylococcus aureus bacteria. These novel platforms have great potential to become excellent tools for biological or medical diagnostics as an alternative to more common silver or gold SERS platforms.
Carbohydrate Polymers, Mar 1, 2018
The complexation of pteroic acid and pterine, subunits of folic acid, with native cyclodextrins (... more The complexation of pteroic acid and pterine, subunits of folic acid, with native cyclodextrins (α-, β-, and γ-CDs) was studied in solution (UV-vis), and in the solid state (thermal analysis, IR and Raman). UV-vis titrations at pH = 7.4 provided data regarding stoichiometry of the formed complexes as well as their associations constants. Stability of the complexes increases in the series: γ-CD < β-CD < < α-CD for pterine, and γ-CD < α-CD < < β-CD for pteroic acid. The mode of complexation was further exploited by molecular modeling studies (docking studies, PM6) showing additionally changes in conformation of pteroic acid upon complexation. Comparison of the association constants of the complexes of pterine and pteroic acid with native cyclodextrins with data obtained for analogous complexes with folic acid shows that all folic acid complexes are less stable than those formed from its subunits.
Applied Physics Letters, Mar 22, 2010
The organic conductor α-[bis(ethylenedithio)tetrathiafulvalene]2I3 undergoes a ferroelectric tran... more The organic conductor α-[bis(ethylenedithio)tetrathiafulvalene]2I3 undergoes a ferroelectric transition due to the Wigner-crystal-like charge ordering. The present paper reports the direct observation of 180° polar domains growing in the ferroelectric phase by means of optical second-harmonic generation interferometry. Mapping observation of the nonlinear optical interference revealed the development of large polar domains, illustrating a strong tendency of single-domain growth in the ferroelectric compound. The domain structures were varied when the crystal was annealed above the transition temperature and recooled into the ferroelectric phase. The variation indicates the mobile nature of the domains in the ferroelectric organic conductor.
Analyst, 2015
Efficient and low-cost surface-enhanced Raman scattering (SERS) substrates based on Au coated zin... more Efficient and low-cost surface-enhanced Raman scattering (SERS) substrates based on Au coated zinc oxide layers for the detection of neopterin were prepared. These substrates showed high sensitivity to p-mercaptobenzoic acid (p-MBA) at a low concentration of 10 −9 M and an enhancement factor of over 10 7 was achieved. The uniform density of SERS-active "hot-spots" on a Si/ZnO/Au surface results in high reproducibility towards detecting p-MBA at 50 different, randomly selected positions on a single substrate (RSD = 9%) and on six different SERS substrates prepared under identical conditions (RSD = 11%). These SERS substrates show good performance in the detection of neopterin, a biologically important molecule whose concentration levels reflect the stage of activation of the cellular immune system, which is of value in the studies of pathogenesis and progression of various diseases. The detection limit is found to be as low as 1.4 nmol L −1 in blood plasma, which is comparable to that of classic ELISA methods. The average relative standard deviation (RSD) of the proposed method is less than 10%. Moreover, this label-free strategy of detection gives exact results over a large range, reflecting clinically relevant neopterin concentrations in body fluids. The detection and quantification of neopterin levels in blood or urine might be useful in clinical practice for monitoring the disease activity during treatment and for early detection of many infections and autoimmune, inflammatory, and malignant diseases. † Electronic supplementary information (ESI) available. See
International Journal of Molecular Sciences
In this study, the intrinsic surface-enhanced Raman spectroscopy (SERS)-based approach coupled wi... more In this study, the intrinsic surface-enhanced Raman spectroscopy (SERS)-based approach coupled with chemometric analysis was adopted to establish the biochemical fingerprint of SARS-CoV-2 infected human fluids: saliva and nasopharyngeal swabs. The numerical methods, partial least squares discriminant analysis (PLS-DA) and support vector machine classification (SVMC), facilitated the spectroscopic identification of the viral-specific molecules, molecular changes, and distinct physiological signatures of pathetically altered fluids. Next, we developed the reliable classification model for fast identification and differentiation of negative CoV(−) and positive CoV(+) groups. The PLS-DA calibration model was described by a great statistical value—RMSEC and RMSECV below 0.3 and R2cal at the level of ~0.7 for both type of body fluids. The calculated diagnostic parameters for SVMC and PLS-DA at the stage of preparation of calibration model and classification of external samples simulating ...
Journal of Biophotonics
Selectin ligands are present on the surface of tumor cells, for this reason lowering the L‐select... more Selectin ligands are present on the surface of tumor cells, for this reason lowering the L‐selectin level in the blood and lymph can indicate presence of the tumor. Therefore the selectin level in the plasma are potential targets for anticancer therapy. We demonstrate the surface enhanced Raman spectroscopy (SERS)‐based sensor for the determination of L‐selectin level in biological samples that can be used in medical diagnosis. The combination of SERS with the method of multivariate analysis as principle component analysis (PCA) allows to strengthen the presented data analysis. The loadings of PCA permit to indicate those vibration modes, that are the most important for the assumed identification (bands at 1574, 1450, 1292 cm−1). Two bands at 1286 and 1580 cm−1 were selected for the determination of the calibration curve (bands intensities I1286/I1580 ratio). The L‐selectin level of biological samples can be read, directly from the calibration curve. The presented sensor is as a sensitive tool with good specificity and selectivity of L‐selectin, even in the case of coexistence of P‐ and E‐selectin.
Biomedicines
We present here that the surface-enhanced Raman spectroscopy (SERS) technique in conjunction with... more We present here that the surface-enhanced Raman spectroscopy (SERS) technique in conjunction with the partial least squares analysis is as a potential tool for the differentiation of pleural effusion in the course of the cancerous disease and a tool for faster diagnosis of lung cancer. Pleural effusion occurs mainly in cancer patients due to the spread of the tumor, usually caused by lung cancer. Furthermore, it can also be initiated by non-neoplastic diseases, such as chronic inflammatory infection (the most common reason for histopathological examination of the exudate). The correlation between pleural effusion induced by tumor and non-cancerous diseases were found using surface-enhanced Raman spectroscopy combined with principal component regression (PCR) and partial least squares (PLS) multivariate analysis method. The PCR predicts 96% variance for the division of neoplastic and non-neoplastic samples in 13 principal components while PLS 95% in only 10 factors. Similarly, when a...
Journal of Molecular Structure, Jul 1, 2006
The films of (BEDT-TTF) 2 XF 6 (where XZP, Sb) and (BEDT-TTF)[Ni(dmit) 2 ] 2 were electrodeposite... more The films of (BEDT-TTF) 2 XF 6 (where XZP, Sb) and (BEDT-TTF)[Ni(dmit) 2 ] 2 were electrodeposited on an intrinsic Si(001) electrode. All samples are examined by scanning electron microscopy, X-ray diffraction data and Raman spectra. The results evidence that new (BEDT-TTF) 2 SbF 6 and (BEDT-TTF)[Ni(dmit) 2 ] 2 phases (compared to those obtained on a common Pt wire) are grown on the silicon electrode.
Analytical Methods, 2016
, 1. SERS substrate characteristic. In order to examine the SERS activity of the (AgNPs/FTO) subs... more , 1. SERS substrate characteristic. In order to examine the SERS activity of the (AgNPs/FTO) substrate, the enhancement factor (EF) was calculated for p-MBA as a standard analyte. The AgNPs/FTO substrate was incubated in 1.0 × 10-6 M p-MBA solution in ethanol for 60 min and then washed with deionized water. The surface enhancement factor (EF) for p-MBA was calculated according to the following equation: Electronic Supplementary Material (ESI) for Analytical Methods.
Analytical Methods, 2016
The article presents surface enhanced Raman scattering (SERS) technique associated with the princ... more The article presents surface enhanced Raman scattering (SERS) technique associated with the principal component analysis (PCA) as a fast and reliable method for the study of interactions between the A, B, AB and O (abr. ABO) blood groups antigen and complementary monoclonal A and B antibodies. The possibility of simultaneous detection and differentiation within the ABO group was evaluated. Using 785 nm excitation wavelength, distinctive spectral changes among all types of the studied blood groups were found for mixtures of red blood cells (RBCs) with the A or B antibody. For PCA analysis, all the spectral data were divided into two main groups based on the type of antibody. The obtained PC scores in the area of antigen-antibody interactions (1311-1345 cm À1) allow differentiation within blood groups with accuracy from 96% to 98%. Additionally, for this region the characteristic marker bands of specific antigen-antibody interactions in relation to both ABO system and antibody were established. The results show excellent segregation of the obtained data and the possibility to use SERS for determination of ABO blood group. Our study proves that SERS is one of the most sensitive techniques for investigations of biological samples and may be used as a new tool that provides one-step comprehensive and reliable medical diagnosis.
Analytical and Bioanalytical Chemistry, Jun 16, 2018
One of the potential applications of surface-enhanced Raman spectroscopy (SERS) is the detection ... more One of the potential applications of surface-enhanced Raman spectroscopy (SERS) is the detection of biological compounds and microorganisms. Here we demonstrate that SERS coupled with principal component analysis (PCA) serves as a perfect method for determining the taxonomic affiliation of bacteria at the strain level. We demonstrate for the first time that it is possible to distinguish different genoserogroups within a single species, Listeria monocytogenes, which is one of the most virulent foodborne pathogens and in some cases contact with which may be fatal. We also postulate that it is possible to detect additional proteins in the L. monocytogenes cell envelope, which provide resistance to benzalkonium chloride and cadmium. A better understanding of this infectious agent could help in selecting the appropriate pharmaceutical product for enhanced treatment.
Journal of Raman Spectroscopy, Jul 27, 2021
We present herein a label-free method based on surface-enhanced Raman spectroscopy (SERS) that wa... more We present herein a label-free method based on surface-enhanced Raman spectroscopy (SERS) that was performed using a silicon-based SERS platform. The differentiation between primary and secondary brain tumors SERS data was completed partial least squares (PLS) method with a very high 85% of accuracy (in only first and second factors), whereas calculated using principal component analysis (PCA) method gives 74% (in two consecutive components). Additionally, due to the fact that the interleukin-10 (IL-10) cytokine receptor may act in cancer as both an immunosuppressive and an immunostimulant factor, the correlation between the tumor grading and the cytokine receptor are presented. Obtained data indicate that the function of IL-10 cytokine receptor subunit alpha most probably depends or is closely related to the tumor stage. K E Y W O R D S brain tumors, cytokine, interleukin-10, multivariate analysis, silicon-based SERS platform, surface-enhanced Raman spectroscopy Highlights • The correlations between the brain tumor grading and their IL-10 cytokine receptor level are presented. • Surface-enhanced Raman spectroscopy and the partial least squares regression was applied as methods of differentiations between primary and secondary brain tumors. • The presented protocol of homogenates tissues analysis may open the way for the new cancer therapy. • Presented method of tumor differentiation may improve the diagnostic accuracy.
Synthetic Metals, Apr 1, 2010
The new-(BEDT-TTF) 2 SbF 6 phase was grown by electrodeposition on a Si(0 0 1) electrode. This ne... more The new-(BEDT-TTF) 2 SbF 6 phase was grown by electrodeposition on a Si(0 0 1) electrode. This new phase was characterized by X-ray diffraction (XRD) and electronic conductivity measurements, accompanied by calculations of electronic band structures and Fermi surfaces. Below T = 120 K, a decrease in the electronic conductivity suggests a phase transition, attributed to anion ordering.
Social Science Research Network, 2023
Physica B-condensed Matter, Jun 1, 2012
ABSTRACT A strong electron–phonon coupling effect, referred to as electron–molecular vibration (e... more ABSTRACT A strong electron–phonon coupling effect, referred to as electron–molecular vibration (e–mv) coupling, induces characteristic vibronic signals in the vibrational spectra of organic conductors. This paper discusses a new spectroscopic signal induced by the e–mv coupling effect, and the physical implications of its emergence. This vibronic signal, attributable to an overtone of a molecular vibration, appears with an anti-resonance form in the infrared spectrum of some mixed-valency complexes when the compounds undergo a charge-ordering transition. Based on the results of cluster model calculations, the activation of the overtone signal is interpreted as an indication of the generation of anharmonicity in the electronic potential. This analysis suggests that the series of the complexes should possess potential nonlinear optical abilities, though these compounds have long been viewed as electric conductors having the opposite characteristics of dielectrics that show nonlinear optical properties.
Beilstein Journal of Organic Chemistry, Oct 25, 2017
The complexation of the antifolate pemetrexed (PTX) with native cyclodextrins was studied. This p... more The complexation of the antifolate pemetrexed (PTX) with native cyclodextrins was studied. This process, along with the findings gathered for the structurally related folic acid was treated as a model for exploiting host-guest interactions of this class of guest molecules in the gas phase, in solution and in the solid state. Mass spectrometry was employed for the investigation of the architecture and relative gas-phase stabilities of these supramolecular complexes. The mode of complexation was further tracked by 1D and 2D NMR proving the formation of the exclusion-type complex with α-CD and pseudorotaxane inclusion-type complexes with β-, and γ-CDs. UV-vis titrations at pH 7.4 gave association constants for the obtained complexes. The stability of the complexes increases in the series: α-CD/PTX < γ-CD/PTX << β-CD/PTX. The association of PTX with a monomer cyclodextrin equivalentmethyl α-D-glucopyranoside-was investigated for a deeper understanding of the type of host-guest interactions. Solid state studies of PTX/CDs were performed using FTIR-ATR and Raman spectroscopy techniques.
Physica B-condensed Matter, Jun 1, 2010
ABSTRACT This paper reports the observation of optical second-harmonic generation (SHG) in an org... more ABSTRACT This paper reports the observation of optical second-harmonic generation (SHG) in an organic conductor α′-(BEDT-TTF)2IBr2. The charge-transfer complex undergoes a semiconductor-to-semiconductor transition around 200K due to charge ordering. Activation of SHG manifested that the complex generates ferroelectric polarization in the charge ordered phase. The observation of the image of SHG revealed that the nonlinear optical signal was generated from limited regions of the single crystal. The inhomogeneous distribution of SHG signal is discussed in terms of the possible competition of ferroelectric and non-polar phases in the phase diagram of the compound.
Journal of Raman Spectroscopy, Mar 8, 2015
Novel surface enhanced Raman spectroscopy (SERS) platforms have been prepared and used for the ba... more Novel surface enhanced Raman spectroscopy (SERS) platforms have been prepared and used for the bacteria detection. Unlike typical, expensive SERS platforms prepared from gold or silver, the presented platforms are prepared using copper. A new, simple, cost-efficient and fast high pressure method is used for platform fabrication, through the decomposition of copper hydride. The platform enhancement factors are verified using the malachite green isothiocyanate as a standard. The platforms exhibit extremely high SERS enhancement factors depending on pressure used for their preparation. The calculated enhancement factors have been found in the range between 1.5 × 10 6 and 4.6 × 10 7. The SERS spectra reproducibility is established both across a single platform and among different platforms. The average spectral correlation coefficient (Γ) has been calculated to be 0.82. Fully characterized SERS platforms have then been used for detecting Staphylococcus aureus bacteria. These novel platforms have great potential to become excellent tools for biological or medical diagnostics as an alternative to more common silver or gold SERS platforms.
Carbohydrate Polymers, Mar 1, 2018
The complexation of pteroic acid and pterine, subunits of folic acid, with native cyclodextrins (... more The complexation of pteroic acid and pterine, subunits of folic acid, with native cyclodextrins (α-, β-, and γ-CDs) was studied in solution (UV-vis), and in the solid state (thermal analysis, IR and Raman). UV-vis titrations at pH = 7.4 provided data regarding stoichiometry of the formed complexes as well as their associations constants. Stability of the complexes increases in the series: γ-CD < β-CD < < α-CD for pterine, and γ-CD < α-CD < < β-CD for pteroic acid. The mode of complexation was further exploited by molecular modeling studies (docking studies, PM6) showing additionally changes in conformation of pteroic acid upon complexation. Comparison of the association constants of the complexes of pterine and pteroic acid with native cyclodextrins with data obtained for analogous complexes with folic acid shows that all folic acid complexes are less stable than those formed from its subunits.
Applied Physics Letters, Mar 22, 2010
The organic conductor α-[bis(ethylenedithio)tetrathiafulvalene]2I3 undergoes a ferroelectric tran... more The organic conductor α-[bis(ethylenedithio)tetrathiafulvalene]2I3 undergoes a ferroelectric transition due to the Wigner-crystal-like charge ordering. The present paper reports the direct observation of 180° polar domains growing in the ferroelectric phase by means of optical second-harmonic generation interferometry. Mapping observation of the nonlinear optical interference revealed the development of large polar domains, illustrating a strong tendency of single-domain growth in the ferroelectric compound. The domain structures were varied when the crystal was annealed above the transition temperature and recooled into the ferroelectric phase. The variation indicates the mobile nature of the domains in the ferroelectric organic conductor.
Analyst, 2015
Efficient and low-cost surface-enhanced Raman scattering (SERS) substrates based on Au coated zin... more Efficient and low-cost surface-enhanced Raman scattering (SERS) substrates based on Au coated zinc oxide layers for the detection of neopterin were prepared. These substrates showed high sensitivity to p-mercaptobenzoic acid (p-MBA) at a low concentration of 10 −9 M and an enhancement factor of over 10 7 was achieved. The uniform density of SERS-active "hot-spots" on a Si/ZnO/Au surface results in high reproducibility towards detecting p-MBA at 50 different, randomly selected positions on a single substrate (RSD = 9%) and on six different SERS substrates prepared under identical conditions (RSD = 11%). These SERS substrates show good performance in the detection of neopterin, a biologically important molecule whose concentration levels reflect the stage of activation of the cellular immune system, which is of value in the studies of pathogenesis and progression of various diseases. The detection limit is found to be as low as 1.4 nmol L −1 in blood plasma, which is comparable to that of classic ELISA methods. The average relative standard deviation (RSD) of the proposed method is less than 10%. Moreover, this label-free strategy of detection gives exact results over a large range, reflecting clinically relevant neopterin concentrations in body fluids. The detection and quantification of neopterin levels in blood or urine might be useful in clinical practice for monitoring the disease activity during treatment and for early detection of many infections and autoimmune, inflammatory, and malignant diseases. † Electronic supplementary information (ESI) available. See
International Journal of Molecular Sciences
In this study, the intrinsic surface-enhanced Raman spectroscopy (SERS)-based approach coupled wi... more In this study, the intrinsic surface-enhanced Raman spectroscopy (SERS)-based approach coupled with chemometric analysis was adopted to establish the biochemical fingerprint of SARS-CoV-2 infected human fluids: saliva and nasopharyngeal swabs. The numerical methods, partial least squares discriminant analysis (PLS-DA) and support vector machine classification (SVMC), facilitated the spectroscopic identification of the viral-specific molecules, molecular changes, and distinct physiological signatures of pathetically altered fluids. Next, we developed the reliable classification model for fast identification and differentiation of negative CoV(−) and positive CoV(+) groups. The PLS-DA calibration model was described by a great statistical value—RMSEC and RMSECV below 0.3 and R2cal at the level of ~0.7 for both type of body fluids. The calculated diagnostic parameters for SVMC and PLS-DA at the stage of preparation of calibration model and classification of external samples simulating ...
Journal of Biophotonics
Selectin ligands are present on the surface of tumor cells, for this reason lowering the L‐select... more Selectin ligands are present on the surface of tumor cells, for this reason lowering the L‐selectin level in the blood and lymph can indicate presence of the tumor. Therefore the selectin level in the plasma are potential targets for anticancer therapy. We demonstrate the surface enhanced Raman spectroscopy (SERS)‐based sensor for the determination of L‐selectin level in biological samples that can be used in medical diagnosis. The combination of SERS with the method of multivariate analysis as principle component analysis (PCA) allows to strengthen the presented data analysis. The loadings of PCA permit to indicate those vibration modes, that are the most important for the assumed identification (bands at 1574, 1450, 1292 cm−1). Two bands at 1286 and 1580 cm−1 were selected for the determination of the calibration curve (bands intensities I1286/I1580 ratio). The L‐selectin level of biological samples can be read, directly from the calibration curve. The presented sensor is as a sensitive tool with good specificity and selectivity of L‐selectin, even in the case of coexistence of P‐ and E‐selectin.
Biomedicines
We present here that the surface-enhanced Raman spectroscopy (SERS) technique in conjunction with... more We present here that the surface-enhanced Raman spectroscopy (SERS) technique in conjunction with the partial least squares analysis is as a potential tool for the differentiation of pleural effusion in the course of the cancerous disease and a tool for faster diagnosis of lung cancer. Pleural effusion occurs mainly in cancer patients due to the spread of the tumor, usually caused by lung cancer. Furthermore, it can also be initiated by non-neoplastic diseases, such as chronic inflammatory infection (the most common reason for histopathological examination of the exudate). The correlation between pleural effusion induced by tumor and non-cancerous diseases were found using surface-enhanced Raman spectroscopy combined with principal component regression (PCR) and partial least squares (PLS) multivariate analysis method. The PCR predicts 96% variance for the division of neoplastic and non-neoplastic samples in 13 principal components while PLS 95% in only 10 factors. Similarly, when a...