Designing a highly sensitive and efficient functionalized electrode for precise drug analysis remains a significant challenge. In this work, an electrochemical sensor based on a glassy carbon electrode (GCE) modified with phenyl diazonium salts (ph) and electrochemically reduced graphene oxide (ERGO), labeled GCE/ph/ERGO, was developed for the detection of paracetamol (PAR) in pharmaceutical matrices using square wave voltammetry (SWV). The modified electrode was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). Compared to the bare GCE, the GCE/ph/ERGO sensor demonstrated significantly improved conductivity and anodic current peak for PAR over two orders of magnitude higher, indicating a substantial enhancement in electrochemical performance. Under optimized conditions, the developed sensor exhibited a low detection limit of 18.2 nM and a quantification limit of 60.6 nM. Precision studies yielded relative standard deviations (RSDs) below 8%. The sensor demonstrated excellent selectivity in the presence of common pharmaceutical excipients and high accuracy in the analysis of generic pharmaceutical formulations, with results comparable to those obtained by the HPLC technique. These findings confirm the sensor’s reliability, stability, robustness, and suitability for routine analysis of PAR in pharmaceutical samples.

In this study, a new and simple glassy carbon electrode modified with carbon nanohorns (SWCNH/GCE) was used for the determination of Cr(VI) in aqueous matrices via adsorptive cathodic stripping voltammetry (AdCSV). The modified electrode was characterized via field emission scanning electron microscopy and cyclic voltammetry, which revealed a homogeneous distribution of spherical agglomerates of SWCNH on the electrode surface. The modification increased the electrochemically active area from 0.10 cm² ± 0.01 (GCE) to 0.16 cm² ± 0.01 (SWCNH/GCE). The optimized analytical conditions were as follows: a supporting electrolyte (0.15 mol L⁻¹ HCl), an accumulation potential of 0.8 V versus Ag/AgCl, and an accumulation time of 240 s. Validation of the analytical methodology was performed, obtaining a linear range between 20 and 100 µg L⁻¹, a limit of detection of 3.5 µg L⁻¹, and a limit of quantification of 11.6 µg L⁻¹ with good accuracy and precision. The method was applied to the analysis of spiked tap water samples, and the results were compared using a flame atomic absorption spectrophotometer (FAAS) with no significant statistical differences.

This paper presents an application for a molybdenum disulfide nanomaterial with multiwalled carbon nanotubes (MoS₂@MWCNT/E) in a modified electrode substrate for the detection of uric acid (UA). The modified electrode generates a substantial three-fold increase in the anodic peak current for UA compared to the unmodified MWCNT electrode (MWCNT/E). The MoS₂@MWCNT/E surface was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS). The achieved detection limit stood at 0.04 µmol/L, with a relative standard deviation (RSD) of 2.0% (n = 10). The method’s accuracy, assessed through relative error and percent recovery, was validated using a urine standard solution spiked with known quantities of UA.

Wild edible mushrooms are a popular food considering their nutritional value. However, some mushroom species can harm human health by accumulating some elements excessively. To evaluate the pollution level of toxic elements in wild edible and non-edible mushrooms from two private natural areas in the Altos de Cantillana mountain range in Central Chile (Altos de Cantillana Natural Reserve and Cerro Poqui Nature Sanctuary) present in them were quantified. All mushrooms contained Pb, Zn, Fe, Cu, and Ni. Mushrooms obtained in Los Altos de Cantillana have higher amounts of metals. In mushrooms of the type Bovista brunnea (sample 27) there are maximum amounts of Pb (566.8 μg/g), Zn (1152.3 μg/g), and Cu (568.6 μg/g) while those of the type Lycoperdon sp. (sample 14) have maximum amounts of Fe (17806.9 μg/g) and Ni (27.6 μg/g). On the other hand, only the species Stereum hirsutum (samples 1 and 4) has very low amounts of As (3.9 μg/g and 6.5 μg/g) and only this one and Phaeoclavulina flaccida contain low amounts of Cd (0.02 μg/g and 0.04 μg/g). On the other hand, Sb and Au were not found in any sample; all values were < LOQ (Limit of quantification). Although intraspecies differences were observed, not all were significant. It is important to highlight the analysis of wild mushroom species that people can consume, such as the genus Cyttaria , which should be evaluated for trace element content.

In this report, hydrothermal treatment of a carbon-based electrode modified with neodymium oxide markedly enhanced the electroactive and conductive properties of the electrode.

This report presents a novel protocol for the recovery and utilization of recycled manganese oxide from used batteries through hydrothermal (HT) treatment. The recovered and treated material showed high activity towards rutin electro-oxidation (RT) on a screen-printed carbon electrode (SPCE) modified with recovered and treated MnO₂ within a hydrothermal reactor. Material characterization using scanning electron microscopy (SEM) and density distribution and particle size analysis revealed a more homogeneous and less dispersed particle size compared to the untreated material. This treatment increased the electroactive activity of the anodic current for RT by more than 70% compared to the SPCE without MnO₂ treated with HT. The electroanalytical application of this new electrode enabled the detection of RT, with a detection limit of 0.03 µmol/L, and its application in natural samples such as coffee and flavored beverages.