This study reported that NiO/MoS2 based nanocomposite can be used as an electrocatalytic material to detect glucose with high selectivity in a blood serum.

Layered molybdenum diselenide (MoSe2) nanosheets were formed by the weak Van der Waals forces of attraction between Se and Mo atoms. MoSe2 has a larger space between the adjacent layers and smaller band gaps in the range of 0.85 to ~ 1.6 eV. In this study, MoSe2 nanosheets decorated nickel oxide (NiO) nanorods have been synthesized by hydrothermal method using sodium molybdate and selenium metal powder. NiO/MoSe2 composite formation was confirmed by powder X-ray diffraction analysis. In addition, the presence of MoSe2 nanosheets on NiO nanorods were confirmed by field emission scanning electron microscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The Nyquist plots of NiO/MoSe2 coated glassy carbon electrode (GCE) was indicated that it had lower charge transfer resistance compared to NiO/GCE and MoSe2/GCE. Furthermore, as-prepared NiO/MoSe2/GCE was used to detect glucose in alkaline solution by cyclic voltammetry and amperometry techniques. The NiO/MoSe2/GCE was exhibited a linear response for the oxidation of glucose from 50 µM to 15.5 mM (R2 = 0.9842) at 0.5 V by amperometry. The sensor response time and the limit of detection were found to be 2 s and 0.6 µM for glucose. Moreover, selectivity of the NiO/MoSe2 sensor was tested in the presence of common interferent molecules such as hydrogen peroxide, fructose, lactose, ascorbic acid, uric acid, and dopamine. It was found that NiO/MoSe2/GCE did not respond to these interfering biomolecules. In addition, NiO/MoSe2/GCE had shown high stability, reproducibility and repeatability. Finally, the practical application of the sensor was demonstrated by detecting glucose in human blood serum with the acceptable recovery.

Background: Microplastics are found to be one of the major emerging contaminants in the environment. Various environmental occurrences cause the macro plastics to degrade slowly into microplastics. Microplastics present in the water bodies may enter into the fish’s body through ingestion of food and also get adsorbed onto the surface of their gills or skin. Objective: Microplastics of polyethylene were chosen to investigate its sorption capacity on fish scales. Dispersion of polyethylene microplastics was studied by using Total dissolved solids meter. Using this dispersion, the sorption effect was studied and it revealed that the microplastics has the sorption ability on the fish scales. Method: Polyethylene microplastics were chosen to investigate its sorption capacity on fish scales of Lutjanus gibbus. The sorption effect of microplastics on fish scales were performed by using polyethylene microplastics obtained by bath sonication and the concentration was studied using Total dissolved solids meter. Using polyethylene microplastics dispersion, the sorption effect was carried out on the scales of Lutjanus gibbus for ten days at 8 oC. Sorption of microplastics on fish scales were characterized by FE-SEM, FT-IR, and Raman spectroscopy. Results: Polymer sorption was confirmed by using optical microscopy and FE-SEM. FT-IR and Raman spectroscopy confirmed the existence of polyethylene microplastics on the fish scale. Moreover, polyethylene microplastics sorption studies were also studied in different pH, various concentrations of NaCl and at different time intervals. Conclusions: We have synthesized microplastics from the bulk polyethylene by NaCl solution. This study confirmed the successful sorption of polyethylene microplastics on the fish scale. Our study revealed that marine water may be a suitable medium to facilitate the polymer sorption on aquatic animals/organisms.

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