Jaromir Hubalek

• Prof. Ing., Ph.D.
• Senior Researcher at Brno University of Technology

Conductive hydrogels represent a promising class of novel materials to interface the human body with electronics; however, there is still a high demand for hydrogels that would truly meet the conductivity requirements for efficient signal transmission between the tissues and the device. To address this demand, herein we report the preparation of a...

The WO 3 nanowires (NWs), fabricated on a commercial Al 2 O 3 -based sensor platform, underwent near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) analysis during ethanol detection. Our findings revealed challenges that may appear in utilizing NAP-XPS studies for studying a real gas sensor in operando conditions. Through NAP-XPS analy...

High-κ dielectric materials are commonly used in microelectronic components due to the technological necessity of increasing the capacitance density of dielectric layers. The thickness of the layer is a crucial parameter of this technology because it has a significant influence on dielectric properties, capacitance density, leakage current density–...

Fabrication of tantalum-based nanotube arrays was accomplished via porous anodic alumina (PAA) assisted electrodeposition (ED). The ED was performed through a PAA template from a conductive bottom face. Mechanically stable, free-standing and spatially-separated TaxOy-nanotubes were electrodeposited potentiostatically at -1.4 V vs. Pt with a high un...

Alignment and patterning of neurons have great importance in some research fields, especially for regenerative medicine and for the formation of artificial neural networks. Alignment of neurons on quartz grooves and parylene cues on quartz substrate was evaluated in this work. The neurons’ alignment on quartz grooves is considered to be topographic...

The continuous emission of nitrous oxides contributes to the overall air pollution and deterioration of air quality. In particular, an effective NO2 sensor capable of low concentration detection for continuous monitoring is demanded for safety, health, and wellbeing. The sensing performance of a metal oxide based sensor is predominantly influenced...

Optofluidic devices combining optics and microfluidics have recently attracted attention for biomolecular analysis due to their high detection sensitivity. Here, we show a silicon chip with tubular microchannels buried inside the substrate featuring temperature gradient (∇T) along the microchannel. We set up an optical fluorescence system consistin...

The determination of the physical properties of fluids—such as the thermal characteristics, which include heat transfer time (Δt)—is becoming more challenging as system sizes shrink to micro- and nanometer scales. Hence, knowledge of these properties is crucial for the operation of devices requiring precise temperature (T) control, such as polymera...

Multielectrode arrays (MEAs) are devices for non-invasive electrophysiological measurements of cell populations. This paper describes a novel fabrication method of MEAs with a fully planar surface. The surface of the insulation layer and the surface of the electrodes were on one plane; we named this device the planar MEA (pMEA). The main advantage...

Gas microsensors based on zinc oxide structures with rod- and needle-like morphology, both integrated via a non-catalyzed vapor-solid mechanism enabled using aerosol-assisted chemical vapor deposition, are developed. Analyses of the films via SEM, TEM, XPS, and water contact angle indicate a higher concentration of oxygen vacancies, higher aspect r...

Selenium nanoparticle modified surfaces attract increasing attention in the field of tissue engineering. Selenium exhibits strong anticancer, antibacterial and anti-inflammatory properties and it maintains relatively low off-target cytotoxicity. In our paper, we present the fabrication, characterization and cytocompatibility of titanium oxide (TiO2...

Individual datasets. File contains raw data from which the graphs were drawn. (DOCX)

Metallothionein II (MT) is a cytosolic, ubiquitous, low-molecular-weight protein present in various tissues of mammals and non-mammals. MTs have a high content of thiol groups (–SH) which can bind mineral micronutrients and xenobiotic heavy metals. In this study, we investigated the electrode processes of MT at a mercury electrode in the presence o...

Chemoresitive gas sensors based on multiple nanowires (M-NWs) randomly grown and electrically inter-connected on the top of interdigitated electrodes (IDEs) and arrays of single nanowires connected between faced nanoelectrodes (A-S-NWs) are developed in this work. These systems, consisting of gas sensitive tungsten oxide nanowires (NWs), are tested...

Arrays of 0- and 1-dimentional noble-metal nanostructures aligned on solid substrates are in demand for nanocatalysis, bio- and optical sensing, or biomolecular analysis. Here we introduce a range of advances based on a systematic research towards the porous-anodic-alumina (PAA)-assisted on-substrate arrays of gold nanostructures, such as rods and...

We developed an advanced method for fabricating microfluidic structures comprising channels and inputs/outputs buried within a silicon wafer based on single level lithography. We etched trenches into a silicon substrate, covered these trenches with parylene-C, and selectively opened their bottoms using femtosecond laser photoablation, forming chann...

Here we report the preparation of low defect blue fluorescent graphene quantum dots (GQDs) through microwave expansion and liquid phase exfoliation (LPE) of graphite flakes with a high preparation yield of 0.63 g of GQDs per 1 g of original graphite substrate. The maximum emission in the prepared GQDs occurs at 467 nm for 370 nm excitation. The pho...

A non-viral tool for the delivery of nucleic acids termed magnetofection was recently developed as a promising transgenic technique with high transfection efficiency for gene delivery into mammalian cells. Despite the fact that transfection efficiency was the objective in the past, the post-transfection cell morphology and the essential gigaseal fo...

Gas nanosensors, comprised of arrays of nanoelectrodes with finger-widths of ~100 nm developed by electron beam lithography and aerosol assisted chemical vapor deposited non-functionalized and Pt-functionalized tungsten oxide nanowires (<100 nm) subsequently integrated across the pairs of electrodes via dielectrophoresis method, are developed in th...

Chemoresistive gas microsensors with highly hydrogen sensitive zinc oxide rods dominated by exposed {100} surfaces are fabricated. The hexagonal rod structures are integrated into micromachined transducing platforms without the need for substrate pre-treatment, via a vapor-solid mechanism enabled using an aerosol-assisted chemical vapor deposition...

Here we report, the preparation of carbon dots showing dual band emission through hydrothermal method. These carbon dots emit 382 nm and 538 nm wavelengths, at 320 nm and 420 nm excitations respectively. However, under 365 nm excitation, these carbon dots show well-resolved emission peaks at 435 nm and 538 nm. The emission peak at 435 nm show excit...

The original version of this article unfortunately contained a mistake. Figure 4 was. The corrected Figure 4 is given below.

The research is focused on water disinfection via new technological concept based on smart combination of nanostructured TiO2 layer and silver nanoparticles (Ag NPs). The TiO2/Ag NPs photocatalytic system was created via anodization of Ti thin film and subsequent UV-assisted and electrochemical pulse deposition of Ag NPs. Morphology of TiO2/Ag NPs...

The characterization of quantum dots (QDs) and their conjugates with bovine serum albumin was done using on-a-chip electrophoresis. Under optimal conditions, bioconjugated QDs were successfully separated from free QDs within ≈10 min. Influence of coupling agent on a quenching of QD fluorescence intensity caused by conjugation to a protein was studi...

The main mechanism of action of platinum-based cytostatic drugs - cisplatin, oxaliplatin and carboplatin - is the formation of DNA cross-links, which restricts the transcription due to the disability of DNA to enter the active site of the polymerase. The polymerase chain reaction (PCR) was employed as a simplified model of the amplification process...

Gas microsensors based on columnar zinc oxide structures (rods and needles) with different aspect ratios and wetting properties are developed via aerosol-assisted chemical vapor deposition. The correlation between their wetting properties and degree of humidity-interference in gas sensing is presented. Gas sensing tests of these systems to hydrogen...

Here we present the gas sensing characterization of single-nanowire sensor array systems based on either non-functionalized or Pt-functionalized single tungsten oxide nanowires towards various concentrations of nitrogen dioxide and ethanol. The sensor systems demonstrate stable and reproducible responses to the tested analytes, showing consistency...

We present a self-compensating system for fixed pattern noise reduction (FPNR) of focal plane arrays (FPAs) of infrared bolometer detectors. It is based on a first-order ΔΣ modulator serving as a non-saturating signal integrator. The demonstrated method suppresses both the effect of bolometer resistance due to non-uniformity across the FPA as well...

Gas-sensitive structures with nanoscale heterojunctions are formed by the co-deposition of WO3-x nanoneedles and Fe2O3 nanoparticles via aerosol-assisted chemical vapour deposition. These composite structures demonstrate enhanced gas sensor performance to ethanol, methanol, acetone, and toluene compared to bare WO3-x nanoneedles devoid of heterojun...

The article introduces a possible chemical separation of a mixture of two compounds on the metal nanorods surface. A silver nanorods surface has been prepared by controlled electrochemical deposition in anodic alumina oxide (AAO) template. Rhodamine 6G and 4-aminothiophenol have been directly applied to the sampling point on a silver nanorods surfa...

Resistive switching in metal oxides, especially in TiO2, has been intensively investigated for potential application in non-volatile memory microdevices. As one of the working mechanisms, a conducting filament consisting of a substoichiometric oxide phase is created within the oxide layer. With the aim of investigating the filament formation in spa...

The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VO...

Magnetic nanoparticles produced using aqueous coprecipitation usually exhibit wide particle size distribution. Synthesis of small and uniform magnetic nanoparticles has been the subject of extensive research over recent years. Sufficiently small superparamagnetic iron oxide nanoparticles easily permeate tissues and may enhance the contrast in magne...

ZnO rods were grown via aerosol-assisted chemical vapor deposition on Si-based micromachined platforms. The photo- and thermo-activated sensor characteristics were evaluated towards carbon monoxide, ethanol and toluene. Results proved photo-activated response at room temperature with improved response and selectivity compared to the thermo-activate...

Microelectrode array systems for their use in single-nanowire-based gas sensor platforms are developed. The topology of the system is designed with the aim of determining the optimal conditions and the factors involved in the selective integration of gas sensitive semiconducting metal oxide nanowires via dielectrophoresis method. Thus various elect...

This paper describes a self-compensating system for fixed pattern noise reduction (FPNR) of focal plane arrays (FPA) of infrared (IR) bolometer detectors. The proposed system used a ΔΣ modulator of first order which operates as non-saturating current integrator. The method also suppressed the self-heating effect as well as the effect of resistance...

Gas microsensors based on ZnO structures grown via aerosol-assisted chemical vapor deposition are fabricated. The photoactivated and thermoactivated gas sensing properties of these systems toward CO are presented. Results demonstrate photoactivated responses at room temperature with improved characteristics, which include 35% higher response and 7%...

This work deals with the new technique called Charge Push-Through technology which is more energy efficient than the currently used approaches. The new energy efficient design regarding utilization of emerging technology such as Energy harvesting (EH) power sources is very promising for future development of energy independent (zero-power) and nono...

The fabrication and characterization of a localized surface plasmon resonance (LSPR) based optical nanosensor, which utilizes highly ordered gold nanoparticles as transducers are presented in this work. The nanoparticles are synthetized using nanodimpled aluminium templates, which were prepared by a selective chemical etching of the porous anodic a...

Neonatal myocytes are a widely used model for modern in-vitro pharmacological screening and tissue engineering of cardiac tissue. The recording of neonatal myocyte electrophysiology in real time has still not been ideally optimised, however. The aim of this study was to evaluate the impact of using different substrates in culture (MEA) chambers on...

Unique mechanical, electronic, chemical, optical, and electrochemical properties of nanosized carbon materials predestine them for numerous potential applications including photocatalysis, electrochemistry, electronics, and optoelectronics. Carbon nanotubes and graphene are some of the most intensively explored carbon allotropes in materials scienc...

An array of semiconducting tungsten-oxide (WOx) nanorods, 100 nm wide and 700 nm long, is synthesized via the porous-anodic-alumina-assisted anodization of tungsten on a substrate and is modified by annealing in air and vacuum. The rods buried in the alumina nanopores are self-anchored to the tungsten layer while their tops are interconnected via g...

An implant of artificial cochlea is the only way how to recover lost hearing in some cases. Fully implantable artificial cochlea in comparison with recent approaches including partially implantable devices is proposed and discussed in this work. The proposed implant consists of subcircuits which are designed in close context to reach optimal perfor...

Chemoresistive micromachined gas sensors with bottom-electrode configuration and based on Pt-functionalized tungsten oxide nanowires are fabricated. The performance and reliability of three types of devices with different electrode gap (5, 10 and 15 μm) are analyzed in dry and humid ambient and towards various analytes (H2, NO2, EtOH, and CO). Resu...

In the paper, planar slot loop antennas are presented. The antennas radiate electromagnetic waves which are polarized perpendicularly to a conductive surface. Therefore, the antennas can be used for on-body or off-body communication. The role of the substrate is played by a three-dimensional textile material. Conductive parts of antennas are fabric...

We propose the ion-beam sputtering deposition providing Ti thin films of desired crystallographic orientation and smooth surface morphology not obtainable with conventional deposition techniques such as magnetron sputtering and vacuum evaporation. The sputtering was provided by argon broad ion beams generated by a Kaufman ion-beam source. In order...

The electrochemical behavior of adenine at a glassy carbon electrode (GCE) modified with a nanocomposite consisting of graphene oxide and polyaniline was investigated by cyclic voltammetry and differential pulse voltammetry. The nanocomposite was synthesized by polymerization and characterized by Raman and UV-vis spectroscopy, and its morphology wa...

This work describes preparation process of free-standing alumina membranes used in sensor devices for separation or purification (increased selectivity, and sensitivity) purposes. Nanoporous alumina membranes were prepared using anodic oxidation of aluminium foil in two types of acidic electrolytes and characterized using scanning electron microsco...

Highly ordered TiO2 nanotube arrays were fabricated by anodic oxidation of titanium thin film in organic electrolyte containing ammonium fluoride and water. The effect of electrolyte composition as well as sputter deposition parameters of titanium thin film on morphology of nanotubes was observed by scanning electron microscopy (SEM) and surface ch...

Here we synthesize a 3-D metal/oxide/metal nanostructured film that merges the benefits of advanced nanocomposite inorganic materials with the flexibility of nonlithographic electrochemical technologies based on so-called porous-anodic-alumina-assisted anodizing of a refractory metal and the point electrodeposition of noble metals. The film is comp...

The making of 3-D nanostructured metal oxide films is an active and competitive area of research, aiming at novel materials with enhanced properties and sensing devices with improved performances. Here we present the preparation procedure and gas sensing behavior of a novel self-assembled 3-D WO3 nanofilm that effectively combines the advantages of...

Mesenchymal stromal cells (MSC) and neutrophils (NP) migration are important factors of the postinfarcted hearts remodeling. These both types of the cells can migrate through cardiac extracellular matrix to the central ischemic region. The quantitative description of MSC and NP migration through collagen matrix is important aim of modern bio-medici...

The construction of an electrochemical sensor based on a gold working electrode modified with gold nanostructures was achieved by galvanic deposition on an anodic alumina nanoporous template. Two approaches were investigated to fabricate the nanostructures of various sizes and shapes. First, gold deposition was performed through a thin alumina temp...

Flexible gas sensor devices are fabricated and optimized by integrating directly, via a single-step vapor-phase deposition method, highly crystalline tungsten oxide nanostructures functionalized with either gold or platinum nanoparticles. Gas tests of these devices show significant improvements with respect to flexible gas sensors based on non-func...

The paper presents a new approach in the field of precise electrolytic conductivity measurements with planar thin- and thick-film electrodes. This novel measuring method was developed for measurement with comb-like electrodes called interdigitated electrodes (IDEs). Correction characteristics over a wide range of specific conductivities were determ...

The present work is aimed to synthesize CdTe/ZnSe core/shell quantum dots (QDs) in an easy way and to explore the possibilities of its application in in vitro imaging of chicken tissue and embryo. The QDs were prepared using microwave irradiation with different temperatures, which is a very easy and less time-consuming method. Subsequently these QD...

The paper presents the first results of research on an artificial cochlea based on a mechanical filter bank that could be produced by MEMS (Micro Electro Mechanical Systems) technologies and power supplied by energy harvesting systems. First, the basic configuration of the artificial cochlea proposed by our team is described. Then, the configuratio...

Vertically aligned multi-walled carbon nanotubes (VA-MWCNTs) with an average diameter below 80 nm and a thickness of the uniform VA-MWCNT layer of about 16 μm were grown in microwave plasma torch and tested for selected functional properties. IR absorption important for a construction of bolometers was studied by Fourier transform infrared spectros...

A non-invasive solution for monitoring of the activity and dehydration of organisms is proposed in the work. For this purpose, a wireless standalone chemical sensor platform using two separate measurement techniques has been developed. The first approach for activity monitoring is based on humidity measurement. Our solution uses new humidity sensor...

The photocatalytic process and various approaches to enhance the efficiency of photocatalysis in metal oxides nanostructures are described in this chapter. The concept of coupling nanostructured metal oxide to another metal oxide or noble metal nanoparticles (NPs) to form hybrid material with novel properties is an attractive and efficient approach...

The screen-printed working electrode (WE) of an electrochemical sensor was modified with multi-walled carbon nanotubes (MWCNTs) and a plasma treatment. The plasma treatment was performed using radio frequency capacitively coupled discharge in Ar/O2, Ar/cyclopropylamine and Ar/NH3. The surface of the WEs was characterized by scanning electron micros...

The aim of this study was to investigate the interaction between lead ions and ethylenediaminetetraacetic acid (EDTA) in plasma. EDTA is widely used in medicine as anticoagulant agent. Understanding of the influence of EDTA on the electrochemical lead ions determination is very suitable for the determination of lead ions at patients with increased...

This review summarized published information in the area of electrochemical detection of influenza virus in 2012 - 2013. The attention was mainly paid to summarize the news in the field of sensors and biosensors for influenza detection. Further, the impedance and quartz crystal microbalance sensing devices are also discussed.

The spectroscopic and electrochemical methods are tested for influenza detection in this study. Cadmium containing quantum dots (QDs) solutions were investigated. Total Cd content is determined by electrochemistry. Utilization of Laser-induced breakdown spectroscopy (LIBS) for QDs analysis in liquid solution deposited on the surface of carrier medi...

The functionality of silver nanostructures prepared by means of electrochemical deposition of silver into the pores of anodic alumina oxide (AAO) template was examined in correlation to electrodeposition conditions. The optical activity as well as the chemical separation ability of prepared nanostructured films was studied. The surface enhanced Ram...

In this study it is described beads based isolation assay terminated by electrochemical analysis of hemagglutinin (HA) using two different cadmium quantum dots (QDs) labelled as CdS and CdTe. The two steps assay was suggested as the first step was the automatic isolation of HA labelled by Cd QDs using glycan modified paramagnetic particles (MPs), a...

In 1957, protein rich in cysteine able to bind cadmium was isolated from horse kidney and named as metallothionein according to its structural properties. Further, this protein and metallothionein-like proteins have been found in tissues of other animal species, yeasts, fungi and plants. MT is as a potential cancer marker in the focus of interest,...

The electroactivity of purine and pyrimidine bases is the most important property of nucleic acids that is very useful for determining oligonucleotides using square wave voltammetry. This study was focused on the electrochemical behavior of adenine-containing oligonucleotides before and after their isolation using paramagnetic particles. Two peaks...

Due to the considerable stability of green fluorescent proteins and their capacity to be readily permutated or mutated, they may be exploited in multiple ways to enhance the functionality of in vitro biosensors. Many possibilities, such as the formation of chimeras with other proteins or antibodies, as well as Förster resonance emission transfer pe...

Microfluidic techniques have been developed intensively in recent years due to lower reagent consumption, faster analysis and possibility of the integration of several analytical detectors into one chip. Electrochemical detectors are preferred in microfluidic systems, whereas liposomes can be used for amplification of the electrochemical signals. T...

The fabrication of self-ordered semiconductor (TiO2) and noble metal (Au) QDs arrays was successfully achieved by advanced nonlithographic template based method, namely using nanoporous alumina template. The emphasis was placed on the successful preparation of QDs arrays with the desired size, homogeneous distribution and optical (especially fluore...