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Development of an automated technique to measure ion route voltages using a surface-modified platinum probe.
Monitoring and determining H2O2 in many industries, treatment plants and biochemical media is important because of its harmful effects even at low concentrations. This work proposes a redox-based colorimetric sensor for the determination of hydrogen peroxide in the presence of antioxidants which are known interferents causing positive errors. selleck chemical On the other hand, the widely used peroxidase-based methods are interfered by enzyme inhibitors. The proposed method consists of two stages, namely antioxidant removal and H2O2 determination. In the first step, antioxidants were removed simply using ABTS radical (ABTS+) oxidant produced by persulfate. After antioxidant elimination, H2O2 in samples was determined by using the CUPRAC colorimetric sensor. The CUPRAC reagent, copper (II)-neocuproine (Cu(II)-Nc), immobilized on a Nafion persulfonate membrane was used for sensor preparation. The light blue Cu(II)-Nc was reduced by H2O2 to the yellow-orange colored Cu(I)-Nc chelate on the sensor, and the absorbance increase at 450 nm was recorded. The LOD and the LOQ values obtained for H2O2 were 0.33 and 1.10 µM, respectively. The proposed assay was validated in terms of linearity, additivity, precision and recovery. The H2O2 contents of spiked food extracts, synthetic serum and certain commercial products (i.e. food sterilization solution, whitening toothpaste and hair bleaching solution) were found to be comparable to the results of peroxidase-ABTS and titanyl sulfate reference assays. In addition, peroxide-type explosive triacetone triperoxide (TATP) was successfully determined in the presence of amine-type antioxidants. The proposed simple and low-cost assay is not inhibited by environmental agents (heavy metals, pesticides, sulfhydryl agents, etc.) adversely affecting enzymatic methods. It is additionally insensitive to turbidity and colored components of complex samples.Carbon quantum dots (CQDs), owing to their characteristic luminescent properties, have become a new favorite in the field of luminescence. They have been widely used in light emitting diode, ion detection, cell-imaging, ect. Herein a facile synthesis method of nitrogen-doped carbon quantum dots (N-CQDs) has been developedviaa one-step hydrothermal of glucose and m-phenylenediamine. The chemical composition, surface functional groups, and crystal structure of so prepared N-CQDs were systematically characterized. The characterizations indicate that nitrogen has been chemically doped in the CQDs and the N-CQDs crystallize in a graphene structure. Photoluminescence (PL) measurements show that the N-CQDs emit strong blue emission under the irradiation of ultraviolet. The emission is excitation-dependent, is resistant to photo bleaching and high ionic strength, and slightly decreases with the increase of temperature. The quantum yield of them is about 17.5%. The PL intensity of N-CQDs quenches linearly with the increase of the concentrations of Fe3+(0.5-1.0 mM) and CrO42-(0.3-0.6 mM), which are a kind of excellent fluorescent probe for the detection of Fe3+ and CrO42-. The quenching mechanism of Fe3+ and CrO42-is verified to be a static quenching mechanism based on inner filter effect. The N-CQDs are also found to be a good cell-imaging reagent of Hela cells.Spectroscopic analysis, density functional theory (DFT) studies and surface enhanced Raman scattering of 4-((3-bromo-5-chloro-2-hydroxybenzylidene)amino)benzoic acid (BCHB) have been studied on different silver colloids concentrations in order to know the particular chemical species responsible for the spectra. For Raman and surface enhanced Raman scattering (SERS) wavenumbers, changes are observed. Observed variations in the modes of ring may be due to interaction of the π-electrons and presence of this indicated that RingII is more inclined than RingI and the BCHB assumes inclined orientation for concentration 10-3 M. Changes in orientation are seen in SERS spectra depending on concentration. In order to determine the electron-rich and poor sites of BCHB, the molecular electrostatic potential was also constructed. The molecular docking studies show that the bindings and interactions with the receptors may be supporting evidence for further studies in design further BCHB pharmaceutical applications.An anthracene-based fluorescence (FL) system was synthesized via a general synthetic procedure. Fourier transform infrared spectroscopy (FTIR), MALDI-MS, and nuclear magnetic resonance spectroscopy (13C and 1H NMR) were carried out to characterize the multi-anthracene containing probe. The photophysical properties of the probe were illustrated via 3D-FL analysis and excitation-emission matrix (EEM) measurements. Density-functional theory (DFT) was applied to optimize the structure of the prepared probe and investigate its molecular interactions with Fe3+. The FL proficiency of the probe was appraised by spectroscopic measurements like Ultraviolet-Visible (UV-Vis) and FL spectroscopies. The simple and highly sensitive probe was able to diagnose ferric ions' low concentrations and detection limit reached upto 0.223 µM with linear working range between 0.22 and 92.00 µM for Fe3+ ions. The efficacy of this fluorescent probe was confirmed by testing for iron determination in environmental samples. Various fluorophores or ionophores could be applied for achieving novel probes by the proposed procedures and for diagnosing diverse metal ions.Accumulating evidence suggests that disrupted insulin signaling is involved in bipolar disorder (BD) pathogenesis. Herein, we aimed to directly explore the potential role of neuronal insulin signaling using an innovative technique based on biomarkers derived from plasma extracellular vesicles enriched for neuronal origin (NEVs). We leveraged plasma samples from a randomized, double-blind, placebo-controlled, 12-week clinical trial evaluating infliximab as a treatment of bipolar depression. We isolated NEVs using immunoprecipitation against neuronal marker L1CAM from samples collected at baseline and weeks 2, 6 and 12 (endpoint) and measured NEV biomarkers using immunoassays. We assessed neuronal insulin signaling at its first node (IRS-1) and along the canonical (Akt, GSK-3β, p70S6K) and alternative (ERK1/2, JNK and p38-MAPK) pathways. A subset of participants (n = 27) also underwent whole-brain magnetic resonance imaging (MRI) at baseline and endpoint. Pre-treatment, NEV biomarkers of insulin signaling were independently associated with cognitive function and MRI measures (i.
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