Unlocking the electrochemical performance of glassy carbon electrodes by surface engineered, sustainable chitosan membranes.

Chitosan coatings, derived from crustacean shell waste, possess inherent biocompatibility and biodegradability, rendering them suitable for various biomedical and environmental applications, including electrochemical biosensing. Its amine and hydroxyl functional groups offer abundant sites for chemical modifications to boost the charge transfer kinetics and provide excellent adhesion, enabling the construction of robust electrode-coating interfaces for electroanalysis. This study explores the role of electrostatically-driven chemical interactions and crosslinking density originating from different chitosan (Cs) and glutaraldehyde (Ga) concentrations in this aspect.

Discriminating macromolecular interactions based on an impedimetric fingerprint supported by multivariate data analysis for rapid and label-free Escherichia coli recognition in human urine.

This manuscript presents a novel approach to address the challenges of electrode fouling and highly complex electrode nanoarchitecture, which are primary concerns for biosensors operating in real environments. The proposed approach utilizes multiparametric impedance discriminant analysis (MIDA) to obtain a fingerprint of the macromolecular interactions on flat glassy carbon surfaces, achieved through self-organized, drop-cast, receptor-functionalized Au nanocube (AuNC) patterns. Real-time monitoring is combined with singular value decomposition and partial least squares discriminant analysis, which enables selective identification of the analyte from raw impedance data, without the use of electric equivalent circuits.

Tailoring of Optical Properties of Methacrylate Resins Enriched by HPHT Microdiamond Particles.

Diamond particles have great potential to enhance the mechanical, optical, and thermal properties of diamond-polymer composites. However, the improved properties of diamond-polymer composites depend on the size, dispersibility, and concentration of diamond particles. In the present study, diamond-polymer composites were prepared by adding the microdiamond particles (MDPs) with different concentrations (0.

Deciphering the Molecular Mechanism of Substrate-Induced Assembly of Gold Nanocube Arrays toward an Accelerated Electrocatalytic Effect Employing Heterogeneous Diffusion Field Confinement.

The complex electrocatalytic performance of gold nanocubes (AuNCs) is the focus of this work. The faceted shapes of AuNCs and the individual assembly processes at the electrode surfaces define the heterogeneous conditions for the purpose of electrocatalytic processes. Topographic and electron imaging demonstrated slightly rounded AuNC (average of 38 nm) assemblies with sizes of ≤1 μm, where the dominating patterns are (111) and (200) crystallographic planes.

Ultrasonic-assisted electrodeposition of Cu-Sn-TiO nanocomposite coatings with enhanced antibacterial activity.

Copper-based coatings are known for their high antibacterial activity. In this study, nanocomposite Cu-Sn-TiO coatings were obtained by electrodeposition from an oxalic acid bath additionally containing 4 g/dm TiO with mechanical and ultrasonic agitation. Ultrasound treatment was performed at 26 kHz frequency and 32 W/dm power.

High-Temperature Oxidation of Heavy Boron-Doped Diamond Electrodes: Microstructural and Electrochemical Performance Modification.

In this work, we reveal in detail the effects of high-temperature treatment in air at 600 °C on the microstructure as well as the physico-chemical and electrochemical properties of boron-doped diamond (BDD) electrodes. The thermal treatment of freshly grown BDD electrodes was applied, resulting in permanent structural modifications of surface depending on the exposure time. High temperature affects material corrosion, inducing crystal defects.

Multifrequency nanoscale impedance microscopy (m-NIM): A novel approach towards detection of selective and subtle modifications on the surface of polycrystalline boron-doped diamond electrodes.

In this paper, we describe the modification of Nanoscale Impedance Microscopy (NIM), namely, a combination of contact-mode atomic force microscopy with local impedance measurements. The postulated approach is based on the application of multifrequency voltage perturbation instead of standard frequency-by-frequency analysis, which among others offers more time-efficient and accurate determination of the resultant impedance spectra with high spatial resolution. Based on the impedance spectra analysis with an appropriate electric equivalent circuit, it was possible to map surface resistance and contact capacitance.

Characterization of Microbial Communities in Acidified, Sulfur Containing Soils.

Over a period of three years, microbial communities in acidified soil with high sulfur content were analyzed. In soil water extracts ureolytic, proteolytic, oxidoreductive, and lipolytic activity were detected. The presented results indicate that the enzymatic activity of soil microbial communities varied considerably over time.

Implementation and validation of multisinusoidal, fast impedance measurements in atomic force microscope contact mode.

This study presents a novel approach to impedance measurements. The methodology discussed is limited to contact in the sample-probe system under ambient conditions without the presence of electrolyte. Comparison with results of direct and alternating current measurements for well-defined metallic surfaces are made.

Dynamic nanoimpedance characterization of the atomic force microscope tip-surface contact.

Nanoimpedance measurements, using the dynamic impedance spectroscopy technique, were carried out during loading and unloading force of a probe on three kinds of materials of different resistivity. These materials were: gold, boron-doped diamond, and AISI 304 stainless steel. Changes of impedance spectra versus applied force were registered and differences in the tip-to-sample contact character on each material were revealed.

Improving AFM images with harmonic interference by spectral analysis.

Atomic force microscopy (AFM) is one of the most sensitive tools for nanoscale imaging. As such, it is very sensitive to external noise sources that can affect the quality of collected data. The intensity of the disturbance depends on the noise source and the mode of operation.

Application of dynamic impedance spectroscopy to atomic force microscopy.

Atomic force microscopy (AFM) is a universal imaging technique, while impedance spectroscopy is a fundamental method of determining the electrical properties of materials. It is useful to combine those techniques to obtain the spatial distribution of an impedance vector. This paper proposes a new combining approach utilizing multifrequency scanning and simultaneous AFM scanning of an investigated surface.