Development of an Activity-Based Ratiometric Electrochemical Switch for Direct, Real-Time Sensing of Pantetheinase in Live Cells, Blood, and Urine Samples.

Pantetheinase is a key biomarker for the diagnosis of acute kidney injury and the monitoring of malaria progression. Currently, existing methods for sensing pantetheinase, also known as Vanin-1, show considerable potential but come with certain limitations, including their inability to directly sense analytes in turbid biofluid samples without tedious sample pretreatment. Here, we describe the first activity-based electrochemical probe, termed VaninLP, for convenient and specific direct targeting of pantetheinase activity in turbid liquid biopsy samples.

Interplay between Electric Field Strength and Number of Short-Duration Pulses for Efficient Gene Electrotransfer.

Electroporation is a method that shows great promise as a non-viral approach for delivering genes by using high-voltage electric pulses to introduce DNA into cells to induce transient gene expression. This research aimed to evaluate the interplay between electric pulse intensity and 100 µs-duration pulse numbers as an outcome of gene electrotransfer efficacy and cell viability. Our results indicated a close relationship between pulse number and electric field strength regarding gene electrotransfer efficacy; higher electric pulse intensity resulted in fewer pulses needed to achieve the same gene electrotransfer efficacy.

Toxicity of different-sized cobalt ferrite (CoFeO) nanoparticles to Oncorhynchus mykiss at early development stages.

As innovative and versatile agents with potential applications in a wide range of fields including medicine, electronics, wastewater treatment, cosmetics, and energy storage devices, magnetic nanoparticles (NPs) are significant attention. However, our knowledge of the harmful effects of different-sized NPs, particularly of their effects on aquatic animals, is limited. In this study, we evaluated the impact of different-sized (sub-2, 5, and 15 nm) cobalt ferrite (CoFeO) NPs on the biological parameters of rainbow trout (Oncorhynchus mykiss) embryos and larvae.

Localised Electrochemical Impedance Spectroscopy of Gold Nanoparticles Labelled Antibodies Probed by Platinum Microstructured Ultramicroelectrode.

This research is focused on enhancing the capabilities of scanning electrochemical impedance microscopy (SEIM) for detecting gold nanoparticle-labelled antibodies using electrochemically modified platinum ultramicroelectrode. The primary objective was to address the high resistance issue encountered in previous measurements with SEIM via the utilization of SEIM probes based on micro-electrodes modified by platinum microstructures, which improved the sensitivity and precision of the detection of targeted biomolecules. The modified probe resulted in a lowered charge transfer resistance by over ten times and a decrease in detection to around 100 fg/mL.

Specificity of carbon nanotube accumulation and distribution in cancer cells revealed by K-means clustering and principal component analysis of Raman spectra.

Single-walled carbon nanotubes (SWCNTs) show great potential for their application as cancer therapeutic nanodrugs, but the efficiency and mechanism of their accumulation in the cell, the modulation of cell activity, and the strong dependence of the results on the type of capping molecule still hinder the transfer of SWCNTs to the clinic. In the present study, we determined the mechanism and sequence of accumulation, distribution and type discrimination of SWCNTs in glioma cells by applying K-means clustering and principal component analysis (PCA) of Raman spectra of cells exposed to SWCNTs capped with either DNA or oligonucleotides (ON). Based on the specific biochemical information uncovered by PCA and further applied to K-means, we show that the accumulation of SWCNT-DNA occurs in two phases.

Microbial Biofuel Cells: Fundamental Principles, Development and Recent Obstacles.

This review focuses on the development of microbial biofuel cells to demonstrate how similar principles apply to the development of bioelectronic devices. The low specificity of microorganism-based amperometric biosensors can be exploited in designing microbial biofuel cells, enabling them to consume a broader range of chemical fuels. Charge transfer efficiency is among the most challenging and critical issues while developing biofuel cells.

Recent Advances in Synthesis and Application of Metal Oxide Nanostructures in Chemical Sensors and Biosensors.

Nanostructured materials formed from metal oxides offer a number of advantages, such as large surface area, improved mechanical and other physical properties, as well as adjustable electronic properties that are important in the development and application of chemical sensors and biosensor design. Nanostructures are classified using the dimensions of the nanostructure itself and their components. In this review, various types of nanostructures classified as 0D, 1D, 2D, and 3D that were successfully applied in chemical sensors and biosensors, and formed from metal oxides using different synthesis methods, are discussed.

Influence of TiO and ZnO Nanoparticles on α-Synuclein and β-Amyloid Aggregation and Formation of Protein Fibrils.

The most common neurological disorders, i.e., Parkinson's disease (PD) and Alzheimer's disease (AD), are characterized by degeneration of cognitive functions due to the loss of neurons in the central nervous system.

Development of Electrostatic Microactuators: 5-Year Progress in Modeling, Design, and Applications.

The implementation of electrostatic microactuators is one of the most popular technical solutions in the field of micropositioning due to their versatility and variety of possible operation modes and methods. Nevertheless, such uncertainty in existing possibilities creates the problem of choosing suitable methods. This paper provides an effort to classify electrostatic actuators and create a system in the variety of existing devices.

Assessment of TiO Nanoparticle Impact on Surface Morphology of Chinese Hamster Ovary Cells.

The process of nanoparticles entering the cells of living organisms is an important step in understanding the influence of nanoparticles on biological processes. The interaction of nanoparticles with the cell membrane is the first step in the penetration of nanoparticles into cells; however, the penetration mechanism is not yet fully understood. This work reported the study of the interaction between TiO nanoparticles (TiO-NPs) and Chinese hamster ovary (CHO) cells using an in vitro model.

Spectroscopic Ellipsometry and Quartz Crystal Microbalance with Dissipation for the Assessment of Polymer Layers and for the Application in Biosensing.

Polymers represent materials that are applied in almost all areas of modern life, therefore, the characterization of polymer layers using different methods is of great importance. In this review, the main attention is dedicated to the non-invasive and label-free optical and acoustic methods, namely spectroscopic ellipsometry (SE) and quartz crystal microbalance with dissipation (QCM-D). The specific advantages of these techniques applied for in situ monitoring of polymer layer formation and characterization, biomolecule immobilization, and registration of specific interactions were summarized and discussed.

Electrochemically Deposited Molecularly Imprinted Polymer-Based Sensors.

This review is dedicated to the development of molecularly imprinted polymers (MIPs) and the application of MIPs in sensor design. MIP-based biological recognition parts can replace receptors or antibodies, which are rather expensive. Conducting polymers show unique properties that are applicable in sensor design.

Evaluation of a Yeast-Polypyrrole Biocomposite Used in Microbial Fuel Cells.

Electrically conductive polymers are promising materials for charge transfer from living cells to the anodes of electrochemical biosensors and biofuel cells. The modification of living cells by polypyrrole (PPy) causes shortened cell lifespan, burdens the replication process, and diminishes renewability in the long term. In this paper, the viability and morphology non-modified, inactivated, and PPy-modified yeasts were evaluated.

Scanning Electrochemical Impedance Microscopy in Redox-Competition Mode for the Investigation of Antibodies Labelled with Horseradish Peroxidase.

Scanning electrochemical microscopy enhanced by electrochemical impedance spectroscopy (SEIM) was applied to detect immobilized antibodies labelled with horseradish peroxidase (Ab-HRP). The localized HRP activity was investigated by the SEIM redox competition (RC-SEIM) mode using hydrogen peroxide as a substrate and hexacyanoferrate as a redox mediator. Electrochemical impedance shows to be related to the consumption of hydrogen peroxide at the ultramicroelectrode.

Molecular Imprinting Technology for Determination of Uric Acid.

The review focuses on the overview of electrochemical sensors based on molecularly imprinted polymers (MIPs) for the determination of uric acid. The importance of robust and precise determination of uric acid is highlighted, a short description of the principles of molecular imprinting technology is presented, and advantages over the others affinity-based analytical methods are discussed. The review is mainly concerned with the electro-analytical methods like cyclic voltammetry, electrochemical impedance spectroscopy, amperometry, etc.

Baker's Yeast-Based Microbial Fuel Cell Mediated by 2-Methyl-1,4-Naphthoquinone.

Microbial fuel cell (MFC) efficiency depends on charge transfer capability from microbe to anode, and the application of suitable redox mediators is important in this area. In this study, yeast viability experiments were performed to determine the 2-methyl-1,4-naphthoquinone (menadione (MD)) influence on different yeast cell species (baker's yeast and yeast cells). In addition, electrochemical measurements to investigate MFC performance and efficiency were carried out.

Toxicological effects of different-sized Co-Fe (CoFeO) nanoparticles on Lepidium sativum L.: towards better understanding of nanophytotoxicity.

Due to their widespread therapeutic and agricultural applicability and usefulness in removing metals and metalloids from water, cobalt ferrite nanoparticles (NPs) are currently receiving increasing attention from researchers. However, their potential phytotoxicity is still poorly understood. Thus, the aim of the current study was to assess the effects of synthesized cobalt ferrite (CoFeO) NPs on biological (morphological, physiological, and biochemical) parameters of edible plant garden-cress (Lepidium sativum L.

Evaluation of electrochemical quartz crystal microbalance based sensor modified by uric acid-imprinted polypyrrole.

Uric acid-imprinted polypyrrole-based (MIP-Ppy) electrochemical quartz crystal microbalance sensor (EQCM) was developed. Experiments and theoretical calculations were focused on molecular interactions between uric acid molecule and: i) polypyrrole imprinted by uric acid (MIP-Ppy) ii) polypyrrole film without any molecular imprints (NIP-Ppy). Resonant frequency differences during electrochemical deposition of MIP-Ppy and NIP-Ppy films were observed and were attributed to the phenomenon of molecule capture within formed Ppy matrix.

Towards Microorganism-Based Biofuel Cells: The Viability of Modified by Multiwalled Carbon Nanotubes.

This research aimed to evaluate the toxic effect of multi-walled carbon nanotubes (MW-CNTs) on yeast cells in order to apply MW-CNTs for possible improvement of the efficiency of microbial biofuel cells. The SEM and XRD analysis suggested that here used MW-CNTs are in the range of 10-25 nm in diameter and their structure was confirmed by Raman spectroscopy. In this study, we evaluated the viability of the yeast cells, affected by MW-CNTs, by cell count, culture optical density and atomic force microscopy.

Hydrothermal synthesis and characterization of nanostructured titanium monoxide films.

At the present time, the formation of titanium monoxide (TiO ) two dimensional (2D) species with distinct composition, size, shape, and a significantly reduced bandgap ( ) value compared to TiO is of great scientific and practical importance. This paper describes our findings investigating Ti surface oxidation for the formation of TiO films possessing a densely-packed nanoplatelet morphology and a low bandgap value. This goal was herein achieved by the hydrothermal treatment of the Ti surface in selenious acid solution kept at a slightly alkaline pH.

Ultra-small methionine-capped Au/Au nanoparticles as efficient drug against the antibiotic-resistant bacteria.

In this study we examined the influence of ultra-small gold and magnetite‑gold nanoparticles (NPs) stabilized with d,l-methionine, FeO@Au@Met, on their antibacterial efficacy against three of twelve the worst bacterial family members included in the World Health Organization (WHO) list. In particular, gram-negative Acinetobacter baumannii, Salmonella enterica and gram-positive methicillin-resistant Staphylococcus aureus and Micrococcus luteus were tested. Apart from the synthesis, gold species reduction and NP stabilization, an excess of methionine has been used herein to detach ultra-small gold NPs from the FeO@Au@Met surface, collect them and investigate.

Electrochemical Deposition and Investigation of Poly-9,10-Phenanthrenequinone Layer.

In this research, a 9,10-phenanthrenequinone (PQ) was electrochemically polymerized on a graphite rod electrode using potential cycling. The electrode modified by poly-9,10-phenanthrenequinone (poly-PQ) was studied by means of cyclic voltammetry, electrochemical impedance spectroscopy, atomic force microscopy and scanning electron microscopy. The poly-PQ shows variations in growth pattern depending on the number of potential cycles for the initiation of polymerization.

Reagent-less amperometric glucose biosensor based on a graphite rod electrode layer-by-layer modified with 1,10-phenanthroline-5,6-dione and glucose oxidase.

A reagent-less amperometric glucose biosensor operating in not-stirred sample solution was developed. A working electrode of the designed biosensor was based on a graphite rod (GR) electrode, which was modified with 1,10-phenanthroline-5,6-dione (PD) and glucose oxidase (GOx). The PD and the GOx were layer-by-layer adsorbed on the GR electrode surface with subsequent drying followed by chemical cross-linking of the adsorbed GOx with glutaraldehyde (GA).

Tuning the ambipolar charge transport properties of tricyanovinyl-substituted carbazole-based materials.

A series of push-pull carbazole-based compounds has been experimentally and theoretically characterized in combination with the X-ray analysis of the corresponding single crystals. The introduction of the strong electron-withdrawing tricyanovinyl group in the carbazole core affords electron-transporting ability in addition to the characteristic hole-transporting properties exhibited by donor carbazole derivatives.