In this work, multi-wall carbon nanotubes (MWNT) were conveniently dispersed into Nafion-ethanol solution, and the MWNT-Nafion-modified glassy carbon electrode (GCE) was described for the simultaneous determination of 2-nitrophenol and 4-nitrophenol. At pH 4.0 phosphate buffer, the reduction peak currents of 2-nitrophenol (at -0.8 V) and 4-nitrophenol (at -1.0 V) increase significantly at the MWNT-Nafion-modified GCE, in comparison with that at the Nafion-modified GCE and the bare GCE. The experimental parameters, such as solution pH of phosphate buffer, accumulation potential and time, and the amounts of MWNT-Nafion onto the GCE surface, were optimized. The reduction peak currents are linear with the concentration of 2-nitrophenol from 5 x 10(-8) to 1 x 10(-5) mol L(-1) and with that of 4-nitrophenol from 1 x 10(-7) to 1 x 10(-5) mol L(-1). The detection limits after 3-min accumulation are 1 x 10(-8) mol L(-1) for 2-nitrophenol and for 4 x 10(-8) mol L(-1) for 4-nitrophenol. This modified electrode was applied to direct determination of 2-nitrophenol and 4-nitrophenol in lake water samples.
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http://dx.doi.org/10.1007/s00216-002-1745-5 | DOI Listing |
JAMA
January 2025
Department of Health Sciences, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam Public Health Research Institute, Amsterdam, the Netherlands.
Importance: Metformin and glyburide monotherapy are used as alternatives to insulin in managing gestational diabetes. Whether a sequential strategy of these oral agents results in noninferior perinatal outcomes compared with insulin alone is unknown.
Objective: To test whether a treatment strategy of oral glucose-lowering agents is noninferior to insulin for prevention of large-for-gestational-age infants.
Anal Biochem
January 2025
Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education, Anhui Provincial Key Laboratory of Synthetic Chemistry and Applications, College of Chemistry and Materials Science, Huaibei Normal University, Huaibei, Anhui 235000, PR China. Electronic address:
Luminol-loaded mesoporous carbon nanospheres (MCs@LU) were utilized to develop a highly sensitive electrochemiluminescence (ECL) sensor for the detection of L-cysteine (L-Cys). L-Cys acted as the coreactant of luminol, and the pore confinement effect of mesoporous carbons (MCs) resulted in a robust ECL signal. Upon optimization, a linear correlation between the ECL intensity and L-Cys concentration was observed over the range of 5.
View Article and Find Full Text PDFAnal Methods
January 2025
Key Laboratory of Oil and Gas Fine Chemicals Ministry of Education, Xinjiang Uyghur Autonomous Region, School of Chemical Engineering and Technology, Xinjiang University, Urumqi 830017, Xinjiang, China.
The unreasonable use of organic dye leads to excessive residues in environmental water, which seriously threatens human health and the natural environment. In this paper, a spherical flower-like magnetic FeO@CoNi layered double hydroxide@silver nanoparticle (FeO@CoNi LDH@Ag NPs) SERS substrate was successfully fabricated electrostatic self-assembly and applied for the sensitive detection of methylene blue (MB) in environmental water. The rapid concentration and separation of the SERS substrate from the water sample could be achieved using an external magnet.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
ZnO-doped CuO nanocomposites (CuO-ZnO NPs) of 1, 3, and 5 mol% were prepared by the solution combustion method using ODH as a fuel (Oxlyl-hydrazide) at 500 °C and calcining at 1000 °C for two hours and the Structural, photocatalytic, and electrochemical properties were investigated by experimental and theoretical methods. X-ray diffraction (XRD) patterns revealed a crystallite size (D) range of 25 to 31 nm for pure CuO and 1, 3, and 5 mol% CuO-ZnO NPs. According to calculations, the optical energy band gap (Eg) of the NPs is between 2.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
December 2024
Centro de Investigaciones Biológicas del Noroeste, S.C., Programa de Acuicultura. Av. Instituto Politécnico Nacional 195, Col. Playa Palo de Santa Rita Sur, La Paz, Baja California Sur 23000, Mexico. Electronic address:
The use of anesthetic agents as pre-operatory treatment to pearl seeding surgery can be stressful to organisms and activate various physiological response mechanisms. This study evaluated some parameters of the systemic antioxidant and immune responses in red abalone (Haliotis rufescens) exposed to 0.25 mL L eugenol (EUB), 3.
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