Samarium tungstate anchored on graphitic carbon nitride composite: A novel electrocatalyst for the ultra-selective electrocatalytic detection of 8-hydroxy-5-nitroquinoline in river water and biological samples

Hydrothermal synthesis and characterization of samarium molybdate nanosheets modified multi-walled carbon nanotubes: Real-time analysis of dimetridazole in environmental and biological samples

Dimetridazole (DMZ) is commonly used as a veterinary drug, resulting in high emissions and environmental pollution and DMZ residues are carcinogenic, genotoxic, and mutagenic to humans. Therefore, it is essential to construct a fast, sensitive and simple sensor to monitor DMZ. In this study, samarium molybdate nanosheets modified multi-walled carbon nanotube composites (SmM/MWCNT) were synthesized to modify GCE for detecting DMZ. The SmM/MWCNT material was also characterized by various analytical and spectroscopic techniques, such as FE-SEM, HRTEM, FT-IR, Raman spectroscopy, XRD, elemental mapping and XPS, to demonstrate the successful synthesis of the composite. Besides, the electrochemical behavior of SmM/MWCNT/GCE for DMZ was also investigated using CV and DPV, and the modified electrode showed good electrochemical sensing performance for DMZ with a low detection limit (0.08 μM), a wide linear range (0.1∼1000 μM), and excellent selectivity. Finally, the SmM/MWCNT/GCE was successfully applied to detect DMZ in environmental and biological samples, and satisfactory recoveries (95%∼105%) were obtained. To the best of our knowledge, the synthesis of SmM/MWCNT and its application in electrochemical sensors are reported for the first time, which demonstrates that it can provide a new route for real-time monitoring of environmental pollutants.

Construction of Cu2Y2O5/g-C3N4 Novel Composite for the Sensitive and Selective Trace-Level Electrochemical Detection of Sulfamethazine in Food and Water Samples

The most frequently used sulfonamide is sulfamethazine (SMZ) because it is often found in foods made from livestock, which is hazardous for individuals. Here, we have developed an easy, quick, selective, and sensitive analytical technique to efficiently detect SMZ. Recently, transition metal oxides have attracted many researchers for their excellent performance as a promising sensor for SMZ analysis because of their superior redox activity, electrocatalytic activity, electroactive sites, and electron transfer properties. Further, Cu-based oxides have a resilient electrical conductivity; however, to boost it to an extreme extent, a composite including two-dimensional (2D) graphitic carbon nitride (g-C3N4) nanosheets needs to be constructed and ready as a composite (denoted as g-C3N4/Cu2Y2O5). Moreover, several techniques, including X-ray diffraction analysis, scanning electron microscopy analysis, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy were employed to analyze the composites. The electrochemical measurements have revealed that the constructed g-C3N4/Cu2Y2O5 composites exhibit great electrochemical activity. Nevertheless, the sensor achieved outstanding repeatability and reproducibility alongside a low limit of detection (LOD) of 0.23 µM, a long linear range of 2 to 276 µM, and an electrode sensitivity of 8.86 µA µM-1 cm-2. Finally, the proposed GCE/g-C3N4/Cu2Y2O5 electrode proved highly effective for detection of SMZ in food samples, with acceptable recoveries. The GCE/g-C3N4/Cu2Y2O5 electrode has been successfully applied to SMZ detection in food and water samples.

Enhancing catalytic activity through the construction of praseodymium tungstate decorated on hierarchical three-dimensional porous biocarbon for determination of furazolidone in aquatic samples

Boosting catalytic performance as a vital role for an electrochemical sensor for monitoring various hazardous nitro drugs. Herein, an inexpensive, facile, and eco-friendly construction of praseodymium tungstate decorated on three dimensional porous biocarbon (PrW/3D-PBC) for electrochemical determination of carcinogenic residue furazolidone (FZ). The nanostructured PrW nanoparticles were prepared by solvent evaporation from peroxo-tungstic acid and 3D-PBC was prepared from biomass precursor under the carbonization method. Furthermore, the composite of PrW decorated on 3D-PBC was prepared by an ultrasonic-assisted wet chemical approach. Besides, the composite characterization of crystalline, functional group, degree of carbonization, chemical states, and morphology were utilized by theXRD, FTIR, RAMAN, XPS, and FESEM analysis. These 3D porous carbon decorated PrW nanoparticles facilitate the electrochemical anchoring sites, surface area, and ease of diffusion layers towards the detection of hazardous nitro pollutant FZ by using CV analysis. The low LOD and high sensitivity were achieved by FZ determination through using LSV and DPV techniques. The practical capability of the PrW/3D-PBC/GCE sensor was determined by using aquatic samples to achieve a good recovery result. These results instigate that the PrW/3D-PBC will be an efficient electrocatalytic material for FZ sensor in environmental aquatic samples.