New screen-printed sensor with a boron-doped diamond working electrode (SP/BDDE) was fabricated using a large-area linear antenna microwave chemical deposition vapor system (LA-MWCVD) with a novel precursor composition. It combines the advantages of disposable printed sensors, such as tailored design, low cost, and easy mass production, with excellent electrochemical properties of BDDE, including a wide available potential window, low background currents, chemical resistance, and resistance to passivation. The newly prepared SP/BDDEs were characterized by scanning electron microscopy (SEM) and Raman spectroscopy. Their electrochemical properties were investigated by cyclic voltammetry and electrochemical impedance spectroscopy using inner sphere ([Fe(CN)₆]^4−/3−) and outer sphere ([Ru(NH₃)₆]^2+/3+) redox probes. Moreover, the applicability of these new sensors was verified by analysis of the anti-inflammatory drug lornoxicam in model and pharmaceutical samples. Using optimized differential pulse voltammetry in Britton–Robinson buffer of pH 3, detection limits for lornoxicam were 9 × 10⁻⁸ mol L⁻¹. The oxidation mechanism of lornoxicam was investigated using bulk electrolysis and online electrochemical cell with mass spectrometry; nine distinct reaction steps and corresponding products and intermediates were identified.

Biochar, a biologically originated carbon-rich material derived from the oxygen-limited pyrolysis of biomass, is usually added to the soil for its enrichment, increasing its water-holding capacity and pH. This revolutionary material thus contributes to a reduction in the overall environmental impact and mitigation of climate change. Due to the beneficial properties of this material, especially for electrochemical applications (large active surface area, conductivity, etc.), biochar demonstrates an extremely high capacity for the adsorption and detection of micropollutants simultaneously. However, finding the optimal conditions for the adsorptive and electrochemical properties of prepared biochar-based sensors is crucial. The adsorption efficiency should be sufficient to remove pollutants, even from complex matrices; on the other hand, the electrochemical properties, such as conductivity and charge transfer resistance, are key factors concerning the sensing ability. Therefore, the balanced design of biochar can ensure both the usability and the effectiveness of sensing. To enhance levels of electroactivity that are already high, the pre- or post-modification of biochar can be performed. Such recycled carbon-based materials could be promising candidates among other electrochemical sensing platforms. In this study, different biochar modifications are presented. Utilizing important biochar properties, it should be possible to create a bifunctional platform for removing micropollutants from water systems and simultaneously confirming purification levels via their detection. We reviewed the use of biochar-based materials for the effective removal of micropollutants and the methods for their detection in water matrices.

The rapid, field-ready detection of methamphetamine (MET) directly in sewage under flow remains a bottleneck for public health and law enforcement surveillance. We engineered a low-cost, 3D-printed flow-through electrochemical cell that houses a commercial screen-printed carbon electrode and operates in both non-flow and flow regimes. The platform was validated using the [Ru(NH₃)₆]^3+/2+ couple, confirming negligible kinetic hindrance and suitability for voltammetric sensing under convective transport. Using square wave voltammetry and chronoamperometry, MET was quantified in filtered wastewater, with limits of detection of 15.9 µg L⁻¹ in non-flow and 211.2 µg L⁻¹ in flow conditions. Specificity tests yielded well-separated faradaic responses for the pre precursor α-phenylacetoacetonitrile (APAAN) and for MET, while amphetamine produced only a weak signal, enabling side-by-side discrimination in a single run. To our knowledge, this is the first demonstration of direct electrochemical sensing of MET in flowing wastewater using a 3D-printed flow-through platform. The simple, disposable design provides an actionable foundation for portable, near-real-time sewer surveillance and motivates antifouling/auto-cleaning strategies for long-term deployment.

We investigated the use of boron-doped diamond (BDD) with different surface morphologies for the enhanced detection of nine different peptides by matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS). For the first time, we compared three different nanostructured BDD film morphologies (Continuous, Nanograss, and Nanotips) with differently terminated surfaces (-H, -O, and -F) to commercially available Ground Steel plates. All these surfaces were evaluated for their effectiveness in detecting the nine different peptides by MALDI-MS. Our results demonstrated that certain nanostructured BDD surfaces exhibited superior performance for the detection of especially hydrophobic peptides (e.g., bradykinin 1–7, substance P, and the renin substrate), with a limit of detection of down to 2.3 pM. Further investigation showed that hydrophobic peptides (e.g., bradykinin 1–7, substance P, and the renin substrate) were effectively detected on hydrogen-terminated BDD surfaces. On the other hand, the highly acidic negatively charged peptide adrenocorticotropic hormone fragment 18–39 was effectively identified on oxygen-/fluorine-terminated BDD surfaces. Furthermore, BDD surfaces reduced sodium adduct contamination significantly.