Bioaccumulation of trace metals and genotoxicity responses in Liza aurata as an indicator of industrial pollution

Heavy metal contamination in the coastal and marine ecosystems is becoming a serious risk to aquatic organisms and humans. This study reports the effects, including genetic damage, of accumulations of trace metals on Liza aurata, which is used as a bio-indicator species, in the Payas coast of Iskenderun Bay, north-eastern Mediterranean by COMET Assay. L. aurata were seasonally collected from a sampling site and a reference site for one year. Physicochemical parameters in water and trace metals in the tissues of fish collected from these sites were determined by electrochemical techniques. High DNA damage frequency in L. aurata was observed along the Payas coast of Iskenderun Bay compared to the reference site because of pollutants. The detected high levels of Cd, Pb, Fe and Cu accumulation in L. aurata exceed the maximum levels allowed by the national and international limit values. Significant positive correlations between Cd, Pb, Hg, Cr, Fe, Zn, and Cu accumulations and DNA damage parameters were observed in the present study. Additionally, we first reported the successful use of the electrochemical technique in the determination of trace metal concentrations in mullet. Moreover, L. aurata constitutes a key tool as a sentinel organism for biomonitoring of coastal ecosystems. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.https://doi.org/10.1007/s10646-022-02591-

Efficient Direct-Methanol Fuel Cell Based on Graphene Quantum Dots/Multi-walled Carbon Nanotubes Composite

Direct-methanol fuel cells are proton-exchange fuel cell in which methanol is used as the fuel. The important advantage of these fuel cells is the simplicity of transport and storage of methanol. In this study, methanol fuel cell electrocatalysts including graphene quantum dots (GQDs), functionalized multi-walled carbon nanotubes (f-MWCNTs) and GQDs/f-MWCNTs composite were synthesized. The structures of synthesized electrocatalysts were highlighted by scanning electron microscope (SEM), raman spectroscopy, UV–vis spectroscopy, fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and x-ray diffraction (XRD) method. After that, the effective surface areas (ESA) of GQDs, f-MWCNTs and GQDs/f-MWCNTs were calculated. Finally, GQDs/f-MWCNTs composite modified glassy carbon electrode (GQDs/f-MWCNTs/GCE) showed highest current signals for methanol oxidation than those of comparable GQDs/GCE and f-MWCNTs/GCE. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

A new approach for electrochemical detection of organochlorine compound lindane: Development of molecular imprinting polymer with polyoxometalate/carbon nitride nanotubes composite and validation

Organochlorine compounds such as gamma-lindane (γ-LND) are very toxic and important ubiquitous contaminants in the environment. In this report, new molecular imprinted sensor on polyoxometalate (POM, H3PW12O40)/carbon nitride nanotubes (C3N4 NTs) composite were prepared for γ-LND detection. The structures of C3N4 NTs and H3PW12O40/C3N4 NTs composite were highlighted by scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive x-ray analysis (EDX), x ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). γ-LND imprinted electrode was prepared in the presence of 100.0 mM pyrrole containing 25.0 mM γ-LND. The analytical results have revealed that 1.0 × 10−10−1.0 × 10−8 M and 2.0 × 10−11 M were found as linearity range and the detection limit (LOD). Furthermore, the developed sensor was examined in terms of stability, repeatability, reproducibility and reusability. Finally, the imprinted sensor was applied to orange juice samples having high recovery. © 2020 Elsevier B.V

Heterostructures of mesoporous TiO 2 and SnO 2 nanocatalyst for improved electrochemical oxidation ability of vitamin B6 in pharmaceutical tablets

The detection of water soluble vitamins using electrochemical method is widely established in pharmaceutical quality control laboratories, and especially the recent advances in hybrid heterostrucure nanomaterials has devoted to enhance the significant analytical parameters like sensitivity, selectivity and fast response time. Herein, we report the synthesis of a hybrid heterostructure comprising SnO 2 nanoparticles supported mesoporous TiO 2 , and the obtained nanocomposite were fabricated over glassy carbon electrode (GCE) for the electrochemical oxidation of vitamin B 6 in pharmaceutical tablets. The designed SnO 2 -TiO 2 /GC modified electrode exhibits well-defined oxidation peak with lowering over-potential and larger signal response compared to the pristine counterparts, and it is mainly due to the formation of abundant active surface layer offered by SnO 2 cocatalyst, and thus significantly enhances the electrochemical surface area. Differential pulse voltam

Fe@Ag nanoparticles decorated reduced graphene oxide as ultrahigh capacity anode material for lithium-ion battery

In the present study, we report the synthesis of Fe@Ag nanoparticles/2-aminoethanethiol functionalized reduced graphene oxide (rGO) composite (Fe@AuNPs-AETrGO) and its application as an improved anode material for lithium-ion batteries (LIBs). The structure of the Fe@AgNPs-AETrGO composite was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical performance was investigated at different charge/discharge current rates by using CR2032 coin-type cells and cyclic voltammetry (CV). It was found that the spherical Fe@AuNPs were highly dispersed on the rGO sheets. Moreover, the Fe@AuNPs-AETrGO composite showed high specific gravimetric capacity of about 1500 mAh g−1 and long-term cycle stability