Determination of Selected Pesticide Residues in River Water Using SBSE Technique

The analytical procedure based on stir‑bar sorptive extraction technique, for the determination of selected pesticide residues (diazinon, malathion, cyprodinyl, penconazole, fludioxonyl, pyriproxyfen, boscalid, pyraclostrobin) is described. Analysis was performed using the commercial TwisterTM stir bar for sorptive extraction. It consists of a 2.0‑cm‑long glass‑encapsulated magnetic stir bar externally coated with PDMS. The extracts were off‑line analyzed using fast GC‑MS in SIM mode. Optimized conditions were established as follows concerning extraction time, stirring speed, aqueous medium characteristics (ionic strength and polarity) respectively: 120 min (700 rpm), addition of 4 g of sodium chloride, no addition of methanol as organic modifier, and 30 min ultrasonic desorption in acetonitrile. Recoveries ranged from 38 % to 58 % (RSD < 15 %, n = 6). Validated limits of quantification in matrix were between 1.6 ngL−1 and 548.8 ngL−1, depending on the compound

Ethanol and NaCl-Induced Gold Nanoparticle Aggregation Toxicity toward DNA Investigated with a DNA/GCE Biosensor

Engineered nanomaterials are becoming increasingly common in commercial and consumer products and pose a serious toxicological threat. Exposure of human organisms to nanomaterials can occur by inhalation, oral intake, or dermal transport. Together with the consumption of alcohol in the physiological environment of the body containing NaCl, this has raised concerns about the potentially harmful effects of ingested nanomaterials on human health. Although gold nanoparticles (AuNPs) exhibit great potential for various biomedical applications, there is some inconsistency in the case of the unambiguous genotoxicity of AuNPs due to differences in their shape, size, solubility, and exposure time. A DNA/GCE (DNA/glassy carbon electrode) biosensor was used to study ethanol (EtOH) and NaCl-induced gold nanoparticle aggregation genotoxicity under UV light in this study. The genotoxic effect of dispersed and aggregated negatively charged gold nanoparticles AuNP1 (8 nm) and AuNP2 (30 nm) toward salmon sperm double-stranded dsDNA was monitored by cyclic and square-wave voltammetry (CV, SWV). Electrochemical impedance spectroscopy (EIS) was used for a surface study of the biosensor. The aggregation of AuNPs was monitored by UV-vis spectroscopy. AuNP1 aggregates formed by 30% v/v EtOH and 0.15 mol·L−1 NaCl caused the greatest damage to the biosensor DNA layer

Tuneable properties of boron-doped diamond working electrodes and their advantages for the detection of pesticides

Abstract Boron-doped diamond (BDD) is a versatile carbon material widely utilized in electroanalysis for detecting various organic compounds. In comparison to commonly employed carbon electrode materials, BDD possesses interesting and unique properties. This review article explores important role of adjustable - tuneable BDD characteristics, including boron concentration, sp³/sp² carbon ratio, and surface treatments, in the electrochemical determination of pesticides. Through an intricate interplay of these properties, BDD’s performance in term of sensitivity, selectivity, and resistance to fouling can be optimized. Notably, the exceptional potential window of BDD electrodes extends the detection capabilities into regimes where other materials falter due to oxygen evolution reactions. Furthermore, in the reduction potential range, BDD electrodes (BDDE) offer a safer alternative to toxic mercury-based electrodes. Despite the considerable progress, gaps remain in understanding the comprehensive effects of tuneable BDDE properties on pesticide analysis. Comparative studies exploring the interplay between these properties and their impact on detection, particularly in multianalyte systems and under challenging conditions, are crucial. Addressing issues related to matrix interference and fouling would contribute significantly to the development of robust pesticide sensors. This review provides insights into the critical role of BDD’s properties in pesticide detection and highlights avenues for future research