Eriks Sledevskis - Academia.edu (original) (raw)

Papers by Eriks Sledevskis

Sensors

Field-effect transistor-based biosensors (bio-FETs) are promising candidates for the rapid high-s... more Field-effect transistor-based biosensors (bio-FETs) are promising candidates for the rapid high-sensitivity and high-selectivity sensing of various analytes in healthcare, clinical diagnostics, and the food industry. However, bio-FETs still have several unresolved problems that hinder their technological transfer, such as electrical stability. Therefore, it is important to develop reliable, efficient devices and establish facile electrochemical characterization methods. In this work, we have fabricated a flexible biosensor based on an Al:ZnO thin-film transistor (TFT) gated through an aqueous electrolyte on a polyimide substrate. In addition, we demonstrated techniques for establishing the operating range of such devices. The Al:ZnO-based devices with a channel length/width ratio of 12.35 and a channel thickness of 50 nm were produced at room temperature via magnetron sputtering. These Al:ZnO-based devices exhibited high field-effect mobility (μ = 6.85 cm2/Vs) and threshold voltage ...

Latvian Journal of Physics and Technical Sciences, 2022

Changes in nanostructure morphology and size may result in very different surface wettability. In... more Changes in nanostructure morphology and size may result in very different surface wettability. In this research, the impact of different morphological parameters on the wetting dynamics of ZnO nanostructured layers is studied. Six different morphologies are chosen to determine the specific wetting processes of ZnO nanostructures: nanoneedles, small diameter rods, large diameter rods, nanotubes, nanoplates, and plain thin films. Wetting dynamics is investigated using conventional sessile drop technique and a novel approach based on electrochemical impedance spectroscopy. The results show that the surface of nanostructured ZnO thin films exhibits both hydrophilic and hydrophobic wetting behaviour, depending on nanostructure form, size, and orientation. ZnO nanostructure arrays are a promising platform for electrochemical and optical sensing in aqueous solutions. The full and effective use of the sensor working surface can be ensured only under the condition of complete wetting of the ...

Frontiers in Behavioral Neuroscience

The development of high-throughput behavioral assays, where numerous individual animals can be an... more The development of high-throughput behavioral assays, where numerous individual animals can be analyzed in various experimental conditions, has facilitated the study of animal personality. Previous research showed that isogenic Drosophila melanogaster flies exhibit striking individual non-heritable locomotor handedness. The variability of this trait, i.e., the predictability of left-right turn biases, varies across genotypes and under the influence of neural activity in specific circuits. This suggests that the brain can dynamically regulate the extent of animal personality. It has been recently shown that predators can induce changes in prey phenotypes via lethal or non-lethal effects affecting the serotonergic signaling system. In this study, we tested whether fruit flies grown with predators exhibit higher variability/lower predictability in their turning behavior and higher survival than those grown with no predators in their environment. We confirmed these predictions and found...

Sensors

This research presents a comparative analysis of water-gated thin film transistors based on a cop... more This research presents a comparative analysis of water-gated thin film transistors based on a copper oxide (CuO) semiconductor in the form of a smooth film and a nanostructured surface. A smooth CuO film was deposited through reactive magnetron sputtering followed by annealing in atmosphere at a temperature of 280 ∘C. Copper oxide nanostructures were obtained by hydrothermal synthesis on a preliminary magnetron sputtered 2 nm thick CuO precursor followed by annealing at 280 ∘C. An X-ray diffraction (XRD) analysis of the samples revealed the presence of a tenorite (CuO) phase with a predominant orientation of (002). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies of the samples revealed a highly developed surface with crystallites having a monoclinic syngony and dimensions of 15–20 nm in thickness, 150 nm in length, and 100 nm in height relative to a 2.5 nm height for the CuO crystallites of the smooth film. Electric measurements of the studied devices re...

Latvian Journal of Physics and Technical Sciences, 2022

Changes in nanostructure morphology and size may result in very different surface wettability. In... more Changes in nanostructure morphology and size may result in very different surface wettability. In this research, the impact of different morphological parameters on the wetting dynamics of ZnO nanostructured layers is studied. Six different morphologies are chosen to determine the specific wetting processes of ZnO nanostructures: nanoneedles, small diameter rods, large diameter rods, nanotubes, nanoplates, and plain thin films. Wetting dynamics is investigated using conventional sessile drop technique and a novel approach based on electrochemical impedance spectroscopy. The results show that the surface of nanostructured ZnO thin films exhibits both hydrophilic and hydrophobic wetting behaviour, depending on nanostructure form, size, and orientation. ZnO nanostructure arrays are a promising platform for electrochemical and optical sensing in aqueous solutions. The full and effective use of the sensor working surface can be ensured only under the condition of complete wetting of the ...

Journal of Optoelectronics and Advanced Materials, 2007

Photoimpact on As 2 S 3 films results the modulation of optical refractive-index accompanied by t... more Photoimpact on As 2 S 3 films results the modulation of optical refractive-index accompanied by the modification of interference conditions for light in thin layers. To increase the value of optical reflection amplitude between interference maximum and minimum the amorphous As 2 S 3 films were obtained by thermal evaporation in vacuum onto glass substrates preliminarily coated with aluminium. The monitoring of the reflectivity at wavelength of 532 nm during the evaporation process of As 2 S 3 layer allowed to obtain the As 2 S 3 -Al pattern with initial reflection value of 10-15%. The samples during the experiment were exposed to the light with wavelength of 532 nm with different intensity. An increase of reflectivity up to 75% was observed. This paper presents the studies of dependence for photoinduced changes in reflectivity of As 2 S 3 -Al system on exposure time, light intensity and film thickness. The holographic recording in reflection mode was performed and studied.

Journal of Optoelectronics and Advanced Materials, 2009

Optical second harmonic generation (SHG) observations and precise X-ray diffraction experiments h... more Optical second harmonic generation (SHG) observations and precise X-ray diffraction experiments have been performed on selenium-copper film structures. Selenium-copper structures were obtained by successive thermal evaporation of selenium and ion evaporation of copper onto the glass substrate in vacuum. To determine what compounds have emerged and if the material is crystalline x-ray diffraction (XRD) analysis was performed. The SHG experiment was performed by confocal microscope where the femtosecond radiation from femtosecond laser (180 fs, 80 MHz) was injected. Second harmonic intensity dependence on wavelength of the exciting radiation and on thickness of Cu layer was observed. We found out that adding small amount of Cu increases reflected SH intensity.

Journal of Optoelectronics and Advanced Materials, 2007

Chalcogenide semiconductor films are the classic object for investigation of holographic recordin... more Chalcogenide semiconductor films are the classic object for investigation of holographic recording. Nevertheless optical recording usually is (carried out) on a surface of film without the focusing of a laser beam. Recording method of micro-hologramms on the surface and in the depth (volume) of film layer is interesting for the practical use. It can considerably increase a total informational capacity of recording and storage medium. For this purpose it is necessary to investigate a possibility of optical recording in two and more layers of definite chalcogenide film, in principle. In the present work optical recording was carried out on As 2 Se 3 films by confocal microscope LEICA TCS SP5 at the wavelength 514 and 488 nm. Laser beam was focused up to diametre 0.6 μm on the surface of film and 4-8 μm inside the film respectively. Recording was made by scanning film area from 16 to 64 μm 2 . The readout was performed at wavelength 633 nm by measuring reflection and transmission befor...

Molecules, 2021

Sustainable agricultural practices are still essential due to soil degradation and crop losses. R... more Sustainable agricultural practices are still essential due to soil degradation and crop losses. Recently, the relationship between plants and nanoparticles (NPs) attracted scientists’ attention, especially for applications in agricultural production as nanonutrition. Therefore, the present research was carried out to investigate the effect of Fe3O4 NPs at low concentrations (0, 1, 10, and 20 mg/L) on three genotypes of barley (Hordeum vulgare L.) seedlings grown in hydroponic conditions. Significant increases in seedling growth, enhanced chlorophyll quality and quantity, and two miRNA expression levels were observed. Additionally, increased genotoxicity was observed in seedlings grown with NPs. Generally, Fe3O4 NPs at low concentrations could be successfully used as nanonutrition for increasing barley photosynthetic efficiency with consequently enhanced yield. These results are important for a better understanding of the potential impact of Fe3O4 NPs at low concentrations in agricul...

Latvian Journal of Physics and Technical Sciences, 2021

To increase the sensitivity and efficiency of a gas sensor, nanostructured ZnO and Co3O4 layers w... more To increase the sensitivity and efficiency of a gas sensor, nanostructured ZnO and Co3O4 layers were obtained by hydrothermal synthesis directly on the electrode surface, eliminating the use of binders. Scanning electron microscope images showed that the resulting nanostructured coatings were characterised by good adhesion to the surface and high porosity, which opened up the possibility of their further use in the process of developing a gas sensor. The efficiency of the obtained nanostructured coatings and their sensitivity at room temperature to various concentrations of CO2 were determined. The resistance curves of the samples were obtained as a function of gas concentration in the chamber, for Co3O4 and ZnO nanostructures.

Glyphosate, commonly known by its original trade name Roundup™, is the world’s most widely used h... more Glyphosate, commonly known by its original trade name Roundup™, is the world’s most widely used herbicide. Glyphosate and it metabolites have profound negative environmental impact and long-term toxicity risk including cancerogenity, genotoxicity, endocrine disruption even at concentration levels too low to have a herbicidal effect. Therefore, the detection of these pollutants in low concentrations is an actual and important task. To increase the sensitivity of the sensor, nanostructures were used. To analyze the presence of glyphosate and its metabolites in rye juice, two groups of samples were selected. In the first case, glyphosate at different concentrations was added to the water for irrigation on the first day and then the samples were watered with pure water for 7 days. In the second case, rye was watered with pure water for all 8 days, and glyphosate was artificially added just before the meas...

Beilstein Journal of Nanotechnology, 2018

ZnO nanostructures are promising candidates for use in sensors, especially in electrochemical sen... more ZnO nanostructures are promising candidates for use in sensors, especially in electrochemical sensors and biosensors, due to their unique physical and chemical properties, as well as sensitivity and selectivity to several types of contamination, including heavy metal ions. In this work, using the hydrothermal method, nanostructures of ZnO were synthesized in four different morphologies: nanorods, nanoneedles, nanotubes and nanoplates. To determine the peculiarities of adsorption for each morphology, a series of electrochemical measurements were carried out using these nanostructured ZnO coatings on the working electrodes, using aqueous solutions of Pb(NO3)2 and Cd(NO3)2 as analytes with different concentrations. It was found that the sensitivity of the resulting electrochemical sensors depends on the morphology of the ZnO nanostructures: the best results were achieved in the case of porous nanostructures (nanotubes and nanoplates), whereas the lowest sensitivity corresponded to ZnO ...

Journal of Nanomaterials, 2019

Plants exposed to stress use the variety of gene regulatory mechanisms to achieve cellular homeos... more Plants exposed to stress use the variety of gene regulatory mechanisms to achieve cellular homeostasis, including posttranscriptional regulation of gene expression where microRNAs (miRNAs) play a pivotal role. Since various environmental stress factors such as nanoparticles affect crop productivity and quality, the aim of the present study was to evaluate the genotoxicity level and to estimate miRNA expression level and chlorophyll a level in the magnetite (Fe3O4) nanoparticle-stressed rocket (Eruca sativa Mill.) seedlings grown in hydroponics. Rocket seedlings were exposed to 1 mg/L, 2 mg/L, and 4 mg/L Fe3O4 nanoparticles, and after 5 weeks, seed germination rate, root-shoot elongation, genotoxicity, chlorophyll a, and miRNA expression levels were evaluated. The obtained results indicated that 1 mg/L, 2 mg/L, and 4 mg/L concentrations of Fe3O4 nanoparticles induce low genotoxicity and have a positive effect on the growth and development of rocket seedlings and that nanoparticles ma...

Sensing and Bio-Sensing Research, 2019

 ZnO nanostructures significantly develop surface of the electrode and increase a number of adso... more  ZnO nanostructures significantly develop surface of the electrode and increase a number of adsorption bonds for the DNA immobilization.  From morphologies of nanostructures that have been studied in this research, the ZnO nanotubes exhibit the best sensitivity on the immobilization stage.  The ZnO nanotubes sensor allows unambiguously to distinguish complementary, noncomplementary, and partially complementary DNA sequences for the Trichinella britovi primers in the analyte, as well as to determine the species of the PCR product.

Journal of Nano- and Electronic Physics, 2016

Journal of Nanomaterials, 2017

Development of methods for direct delivery of different bioactive substances into the cell is a p... more Development of methods for direct delivery of different bioactive substances into the cell is a promising and intensively approached area of research. It has become a subject of serious research for multidisciplinary team of scientists working in such areas as physics, biology, and biotechnology. Plant calluses were grown on medium supplemented with different nanoparticles to be used as a model for biotechnological research. Gold nanoparticles with mesoporous silica coating were used as hormone carriers, since they possess many of critical properties required for cellular transportation instrument. Some of those properties are great biocompatibility and controlled release of carried molecules. Significant changes in hormones common impact were detected. The great increase in ploidy numbers, embryogenesis, induction, and methylation level was observed when compared to the “conventional” methods of targeted hormones delivery that embrace usage of Au nanoparticles as a main hormone car...

Latvian Journal of Physics and Technical Sciences, 2015

The present paper presents the method for obtaining core/shell CuO-ZnO nanoparticles and nanocoat... more The present paper presents the method for obtaining core/shell CuO-ZnO nanoparticles and nanocoatings by using a commercially available vacuum coating system. Initially generated Cu-Zn core/shell nanoparticles have been oxidised with a highly reactive atomic oxygen beam. Second-harmonic generation has been observed in the obtained samples. The dependence of second- harmonic intensity on the wavelength of the exciting radiation is shown in the paper.

Journal of Nanomaterials, 2015

The genotoxic effect of cadmium sulfide nanoparticles (CdS NPs) of different sizes in rucola (Eru... more The genotoxic effect of cadmium sulfide nanoparticles (CdS NPs) of different sizes in rucola (Eruca sativaMill.) plants was assessed. It was confirmed that nanoparticles < 5 nm in size were more toxic than larger particles at an identical mass concentration. Significant differences in cell ploidy, as well as in the mitotic index, were detected between control and treated samples. Differences in the DNA banding pattern between control samples and samples after treatment with cadmium sulfide nanoparticles were significant and detected at different places as the appearance or elimination of DNA fragments. Fluorescence images showed that cadmium sulfide nanoparticles smaller than 5 nm in size can diffuse through the membrane and their presence affects the genetic system of the plant.

Sensors

Field-effect transistor-based biosensors (bio-FETs) are promising candidates for the rapid high-s... more Field-effect transistor-based biosensors (bio-FETs) are promising candidates for the rapid high-sensitivity and high-selectivity sensing of various analytes in healthcare, clinical diagnostics, and the food industry. However, bio-FETs still have several unresolved problems that hinder their technological transfer, such as electrical stability. Therefore, it is important to develop reliable, efficient devices and establish facile electrochemical characterization methods. In this work, we have fabricated a flexible biosensor based on an Al:ZnO thin-film transistor (TFT) gated through an aqueous electrolyte on a polyimide substrate. In addition, we demonstrated techniques for establishing the operating range of such devices. The Al:ZnO-based devices with a channel length/width ratio of 12.35 and a channel thickness of 50 nm were produced at room temperature via magnetron sputtering. These Al:ZnO-based devices exhibited high field-effect mobility (μ = 6.85 cm2/Vs) and threshold voltage ...

Latvian Journal of Physics and Technical Sciences, 2022

Changes in nanostructure morphology and size may result in very different surface wettability. In... more Changes in nanostructure morphology and size may result in very different surface wettability. In this research, the impact of different morphological parameters on the wetting dynamics of ZnO nanostructured layers is studied. Six different morphologies are chosen to determine the specific wetting processes of ZnO nanostructures: nanoneedles, small diameter rods, large diameter rods, nanotubes, nanoplates, and plain thin films. Wetting dynamics is investigated using conventional sessile drop technique and a novel approach based on electrochemical impedance spectroscopy. The results show that the surface of nanostructured ZnO thin films exhibits both hydrophilic and hydrophobic wetting behaviour, depending on nanostructure form, size, and orientation. ZnO nanostructure arrays are a promising platform for electrochemical and optical sensing in aqueous solutions. The full and effective use of the sensor working surface can be ensured only under the condition of complete wetting of the ...

Frontiers in Behavioral Neuroscience

The development of high-throughput behavioral assays, where numerous individual animals can be an... more The development of high-throughput behavioral assays, where numerous individual animals can be analyzed in various experimental conditions, has facilitated the study of animal personality. Previous research showed that isogenic Drosophila melanogaster flies exhibit striking individual non-heritable locomotor handedness. The variability of this trait, i.e., the predictability of left-right turn biases, varies across genotypes and under the influence of neural activity in specific circuits. This suggests that the brain can dynamically regulate the extent of animal personality. It has been recently shown that predators can induce changes in prey phenotypes via lethal or non-lethal effects affecting the serotonergic signaling system. In this study, we tested whether fruit flies grown with predators exhibit higher variability/lower predictability in their turning behavior and higher survival than those grown with no predators in their environment. We confirmed these predictions and found...

Sensors

This research presents a comparative analysis of water-gated thin film transistors based on a cop... more This research presents a comparative analysis of water-gated thin film transistors based on a copper oxide (CuO) semiconductor in the form of a smooth film and a nanostructured surface. A smooth CuO film was deposited through reactive magnetron sputtering followed by annealing in atmosphere at a temperature of 280 ∘C. Copper oxide nanostructures were obtained by hydrothermal synthesis on a preliminary magnetron sputtered 2 nm thick CuO precursor followed by annealing at 280 ∘C. An X-ray diffraction (XRD) analysis of the samples revealed the presence of a tenorite (CuO) phase with a predominant orientation of (002). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies of the samples revealed a highly developed surface with crystallites having a monoclinic syngony and dimensions of 15–20 nm in thickness, 150 nm in length, and 100 nm in height relative to a 2.5 nm height for the CuO crystallites of the smooth film. Electric measurements of the studied devices re...

Latvian Journal of Physics and Technical Sciences, 2022

Changes in nanostructure morphology and size may result in very different surface wettability. In... more Changes in nanostructure morphology and size may result in very different surface wettability. In this research, the impact of different morphological parameters on the wetting dynamics of ZnO nanostructured layers is studied. Six different morphologies are chosen to determine the specific wetting processes of ZnO nanostructures: nanoneedles, small diameter rods, large diameter rods, nanotubes, nanoplates, and plain thin films. Wetting dynamics is investigated using conventional sessile drop technique and a novel approach based on electrochemical impedance spectroscopy. The results show that the surface of nanostructured ZnO thin films exhibits both hydrophilic and hydrophobic wetting behaviour, depending on nanostructure form, size, and orientation. ZnO nanostructure arrays are a promising platform for electrochemical and optical sensing in aqueous solutions. The full and effective use of the sensor working surface can be ensured only under the condition of complete wetting of the ...

Journal of Optoelectronics and Advanced Materials, 2007

Photoimpact on As 2 S 3 films results the modulation of optical refractive-index accompanied by t... more Photoimpact on As 2 S 3 films results the modulation of optical refractive-index accompanied by the modification of interference conditions for light in thin layers. To increase the value of optical reflection amplitude between interference maximum and minimum the amorphous As 2 S 3 films were obtained by thermal evaporation in vacuum onto glass substrates preliminarily coated with aluminium. The monitoring of the reflectivity at wavelength of 532 nm during the evaporation process of As 2 S 3 layer allowed to obtain the As 2 S 3 -Al pattern with initial reflection value of 10-15%. The samples during the experiment were exposed to the light with wavelength of 532 nm with different intensity. An increase of reflectivity up to 75% was observed. This paper presents the studies of dependence for photoinduced changes in reflectivity of As 2 S 3 -Al system on exposure time, light intensity and film thickness. The holographic recording in reflection mode was performed and studied.

Journal of Optoelectronics and Advanced Materials, 2009

Optical second harmonic generation (SHG) observations and precise X-ray diffraction experiments h... more Optical second harmonic generation (SHG) observations and precise X-ray diffraction experiments have been performed on selenium-copper film structures. Selenium-copper structures were obtained by successive thermal evaporation of selenium and ion evaporation of copper onto the glass substrate in vacuum. To determine what compounds have emerged and if the material is crystalline x-ray diffraction (XRD) analysis was performed. The SHG experiment was performed by confocal microscope where the femtosecond radiation from femtosecond laser (180 fs, 80 MHz) was injected. Second harmonic intensity dependence on wavelength of the exciting radiation and on thickness of Cu layer was observed. We found out that adding small amount of Cu increases reflected SH intensity.

Journal of Optoelectronics and Advanced Materials, 2007

Chalcogenide semiconductor films are the classic object for investigation of holographic recordin... more Chalcogenide semiconductor films are the classic object for investigation of holographic recording. Nevertheless optical recording usually is (carried out) on a surface of film without the focusing of a laser beam. Recording method of micro-hologramms on the surface and in the depth (volume) of film layer is interesting for the practical use. It can considerably increase a total informational capacity of recording and storage medium. For this purpose it is necessary to investigate a possibility of optical recording in two and more layers of definite chalcogenide film, in principle. In the present work optical recording was carried out on As 2 Se 3 films by confocal microscope LEICA TCS SP5 at the wavelength 514 and 488 nm. Laser beam was focused up to diametre 0.6 μm on the surface of film and 4-8 μm inside the film respectively. Recording was made by scanning film area from 16 to 64 μm 2 . The readout was performed at wavelength 633 nm by measuring reflection and transmission befor...

Molecules, 2021

Sustainable agricultural practices are still essential due to soil degradation and crop losses. R... more Sustainable agricultural practices are still essential due to soil degradation and crop losses. Recently, the relationship between plants and nanoparticles (NPs) attracted scientists’ attention, especially for applications in agricultural production as nanonutrition. Therefore, the present research was carried out to investigate the effect of Fe3O4 NPs at low concentrations (0, 1, 10, and 20 mg/L) on three genotypes of barley (Hordeum vulgare L.) seedlings grown in hydroponic conditions. Significant increases in seedling growth, enhanced chlorophyll quality and quantity, and two miRNA expression levels were observed. Additionally, increased genotoxicity was observed in seedlings grown with NPs. Generally, Fe3O4 NPs at low concentrations could be successfully used as nanonutrition for increasing barley photosynthetic efficiency with consequently enhanced yield. These results are important for a better understanding of the potential impact of Fe3O4 NPs at low concentrations in agricul...

Latvian Journal of Physics and Technical Sciences, 2021

To increase the sensitivity and efficiency of a gas sensor, nanostructured ZnO and Co3O4 layers w... more To increase the sensitivity and efficiency of a gas sensor, nanostructured ZnO and Co3O4 layers were obtained by hydrothermal synthesis directly on the electrode surface, eliminating the use of binders. Scanning electron microscope images showed that the resulting nanostructured coatings were characterised by good adhesion to the surface and high porosity, which opened up the possibility of their further use in the process of developing a gas sensor. The efficiency of the obtained nanostructured coatings and their sensitivity at room temperature to various concentrations of CO2 were determined. The resistance curves of the samples were obtained as a function of gas concentration in the chamber, for Co3O4 and ZnO nanostructures.

Glyphosate, commonly known by its original trade name Roundup™, is the world’s most widely used h... more Glyphosate, commonly known by its original trade name Roundup™, is the world’s most widely used herbicide. Glyphosate and it metabolites have profound negative environmental impact and long-term toxicity risk including cancerogenity, genotoxicity, endocrine disruption even at concentration levels too low to have a herbicidal effect. Therefore, the detection of these pollutants in low concentrations is an actual and important task. To increase the sensitivity of the sensor, nanostructures were used. To analyze the presence of glyphosate and its metabolites in rye juice, two groups of samples were selected. In the first case, glyphosate at different concentrations was added to the water for irrigation on the first day and then the samples were watered with pure water for 7 days. In the second case, rye was watered with pure water for all 8 days, and glyphosate was artificially added just before the meas...

Beilstein Journal of Nanotechnology, 2018

ZnO nanostructures are promising candidates for use in sensors, especially in electrochemical sen... more ZnO nanostructures are promising candidates for use in sensors, especially in electrochemical sensors and biosensors, due to their unique physical and chemical properties, as well as sensitivity and selectivity to several types of contamination, including heavy metal ions. In this work, using the hydrothermal method, nanostructures of ZnO were synthesized in four different morphologies: nanorods, nanoneedles, nanotubes and nanoplates. To determine the peculiarities of adsorption for each morphology, a series of electrochemical measurements were carried out using these nanostructured ZnO coatings on the working electrodes, using aqueous solutions of Pb(NO3)2 and Cd(NO3)2 as analytes with different concentrations. It was found that the sensitivity of the resulting electrochemical sensors depends on the morphology of the ZnO nanostructures: the best results were achieved in the case of porous nanostructures (nanotubes and nanoplates), whereas the lowest sensitivity corresponded to ZnO ...

Journal of Nanomaterials, 2019

Plants exposed to stress use the variety of gene regulatory mechanisms to achieve cellular homeos... more Plants exposed to stress use the variety of gene regulatory mechanisms to achieve cellular homeostasis, including posttranscriptional regulation of gene expression where microRNAs (miRNAs) play a pivotal role. Since various environmental stress factors such as nanoparticles affect crop productivity and quality, the aim of the present study was to evaluate the genotoxicity level and to estimate miRNA expression level and chlorophyll a level in the magnetite (Fe3O4) nanoparticle-stressed rocket (Eruca sativa Mill.) seedlings grown in hydroponics. Rocket seedlings were exposed to 1 mg/L, 2 mg/L, and 4 mg/L Fe3O4 nanoparticles, and after 5 weeks, seed germination rate, root-shoot elongation, genotoxicity, chlorophyll a, and miRNA expression levels were evaluated. The obtained results indicated that 1 mg/L, 2 mg/L, and 4 mg/L concentrations of Fe3O4 nanoparticles induce low genotoxicity and have a positive effect on the growth and development of rocket seedlings and that nanoparticles ma...

Sensing and Bio-Sensing Research, 2019

 ZnO nanostructures significantly develop surface of the electrode and increase a number of adso... more  ZnO nanostructures significantly develop surface of the electrode and increase a number of adsorption bonds for the DNA immobilization.  From morphologies of nanostructures that have been studied in this research, the ZnO nanotubes exhibit the best sensitivity on the immobilization stage.  The ZnO nanotubes sensor allows unambiguously to distinguish complementary, noncomplementary, and partially complementary DNA sequences for the Trichinella britovi primers in the analyte, as well as to determine the species of the PCR product.

Journal of Nano- and Electronic Physics, 2016

Journal of Nanomaterials, 2017

Development of methods for direct delivery of different bioactive substances into the cell is a p... more Development of methods for direct delivery of different bioactive substances into the cell is a promising and intensively approached area of research. It has become a subject of serious research for multidisciplinary team of scientists working in such areas as physics, biology, and biotechnology. Plant calluses were grown on medium supplemented with different nanoparticles to be used as a model for biotechnological research. Gold nanoparticles with mesoporous silica coating were used as hormone carriers, since they possess many of critical properties required for cellular transportation instrument. Some of those properties are great biocompatibility and controlled release of carried molecules. Significant changes in hormones common impact were detected. The great increase in ploidy numbers, embryogenesis, induction, and methylation level was observed when compared to the “conventional” methods of targeted hormones delivery that embrace usage of Au nanoparticles as a main hormone car...

Latvian Journal of Physics and Technical Sciences, 2015

The present paper presents the method for obtaining core/shell CuO-ZnO nanoparticles and nanocoat... more The present paper presents the method for obtaining core/shell CuO-ZnO nanoparticles and nanocoatings by using a commercially available vacuum coating system. Initially generated Cu-Zn core/shell nanoparticles have been oxidised with a highly reactive atomic oxygen beam. Second-harmonic generation has been observed in the obtained samples. The dependence of second- harmonic intensity on the wavelength of the exciting radiation is shown in the paper.

Journal of Nanomaterials, 2015

The genotoxic effect of cadmium sulfide nanoparticles (CdS NPs) of different sizes in rucola (Eru... more The genotoxic effect of cadmium sulfide nanoparticles (CdS NPs) of different sizes in rucola (Eruca sativaMill.) plants was assessed. It was confirmed that nanoparticles < 5 nm in size were more toxic than larger particles at an identical mass concentration. Significant differences in cell ploidy, as well as in the mitotic index, were detected between control and treated samples. Differences in the DNA banding pattern between control samples and samples after treatment with cadmium sulfide nanoparticles were significant and detected at different places as the appearance or elimination of DNA fragments. Fluorescence images showed that cadmium sulfide nanoparticles smaller than 5 nm in size can diffuse through the membrane and their presence affects the genetic system of the plant.