NOPR Collection:

A novel electrochemical biosensor for the detection of ethambutol

2018-07-23T06:03:37Z

Title: A novel electrochemical biosensor for the detection of ethambutol Authors: Chokkareddy, Rajasekhar; Bhajanthri, Natesh Kumar; Redhi, Gan G Abstract: A glassy carbon electrode (GCE) has been fabricated with zinc oxide nanoparticles (ZnONPs) and reduced graphene oxide (RGO) immobilized with horseradish peroxidase enzyme (HRP) for the voltammetric determination of ethambutol. Electrochemical behaviour of ethambutol has been studied with cyclic voltammetry and differential pulse voltammetry. The HRP-ZnONPs-RGO-GCE exhibits high electrooxidation of ethambutol in phosphate buffer solution at pH 7.0 and the electrochemical signal is significantly enhanced. In addition, the proposed biosensor has been characterized by transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The HRP-ZnONPs-RGO-GCE shows an oxidation peak at –0.2 V with CV. Under the optimized conditions, the DPV technique gave good limit of detection and limit of quantification values of 0.0214 μM and 0.6713 μM respectively. The HRP-ZnONPs-RGO-GCE shows excellent background current stability and gives reliable performance with pharmaceutical samples in the terms of sensitivity, reproducibility and repeatability. Page(s): 887-895

Prussian blue/ superactivated carbon composite-modified electrode for detection of p-phenylenediamine

2018-07-23T05:54:57Z

Title: Prussian blue/ superactivated carbon composite-modified electrode for detection of p-phenylenediamine Authors: Hu, Lin; Li, Jin qing; Zhou, Xiao qin; Bai, Tong tong; Cui, Qu jin; Tang, Juan; Xu, Wen yuan Abstract: A novel approach for the selective determination of p-phenylenediamine in aqueous solution using Prussian blue (PB)/ superactivated carbon (SAC) composite-modified glassy carbon electrodes is reported. The chemical constitution and microstructure of PB/SAC composites are studied by SEM, BET and IR data. Due to its unique structure and properties originating from Prussian blue in the superactivated carbon frame, PB/SAC composites show high electrocatalytic activity towards the oxidation of p-phenylenediamine. A special chemical reaction and electron transfer process on the surface of PB/SAC composite-modified GC electrode is proposed and evaluated by cyclic voltammetry and AC impedance in the presence of p-phenylenediamine. The current value of differential pulse voltammetry increases linearly with the p-phenylenediamine concentration in the range 2×10^-7−1×10^-3M with a detection limit of 6.47×10^-8 M (S/N = 3). The relative standard deviation of the waste water samples is < 6% and the recovery rate is 97−104%. These results suggest that the modified electrode has high selection for p-phenylenediamine, good repeatability, and operational stability. The modified electrode has been successfully used to analyze the amount of p-phenylenediamine in water samples. Page(s): 896-904

Synthesis and structure characterization of two cadmium coordination polymers based on μ₂-bridging bidentate hydrazine ligand

2018-07-23T05:50:08Z

Title: Synthesis and structure characterization of two cadmium coordination polymers based on μ₂-bridging bidentate hydrazine ligand Authors: Shanthakumar, D Santhosh; Pradeep, R; Subramani, B; Sivasankar, B N Abstract: Synthesis, single crystal structures, spectral and thermal characteristics of two cadmium coordination polymers, viz., [Cd(NO₃)₂(N₂H₄)₂] (1) [Cd(C₃H₂O₄)(N₂H₄)] (where C₃H₂O₄is malonate) (2) are reported. The μ₂-bridging bidentate binding mode of the crystallographically unique hydrazine ligands in (1) leads to a one-dimensional polymeric structure extending along c axis. The central Cd(II) in (2) exhibits hepta-coordination and is bonded to a unique malonate anion which exhibits a μ₃-bridging pentadentate coordination, extending the structure along the a axis. The bridging bidentate binding of the crystallographically independent hydrazine ligand extends along b axis resulting in a 2-D structure. Page(s): 905-909

Sol-gel synthesis of mesoporous hollow titania microspheres for photodegradation of 4-chlorophenol

2018-07-23T05:44:37Z

Title: Sol-gel synthesis of mesoporous hollow titania microspheres for photodegradation of 4-chlorophenol Authors: Chowdhury, Ipsita Hazra; Naskar, Milan Kanti Abstract: Mesoporous titania (TiO₂) hollow microspheres have been prepared by sol-gel method and characterized by XRD, Raman, FTIR, N₂ adsorption-desorption study, FESEM, TEM and UV-DRS. The FESEM images reveal hollow spherical shaped particles of size 2–4 µm. The BET surface area, total pore volume and average pore diameter of 400 °C-treated sample are found to be 74.52 m² g^-1, 0.23 cm³ g^-1 and 12.37 nm, respectively. The band gap energy of the product is calculated as 3.06 eV. The prepared TiO₂ hollow spheres show ~90% photodegradation of the water pollutant, 4-chlorophenol, within 1 h. The photocatalytic reaction shows pseudo-first order reaction with a rate constant of 0.027 min^-1. The photocatalytic experiments repeated for another three cycles showed no significant changes in the k (min^-1) values, indicating the potential reusability of the material. Page(s): 910-914

NOPR Collection:

A novel electrochemical biosensor for the detection of ethambutol

Prussian blue/ superactivated carbon composite-modified electrode for detection of p-phenylenediamine

Synthesis and structure characterization of two cadmium coordination polymers based on μ2-bridging bidentate hydrazine ligand

Sol-gel synthesis of mesoporous hollow titania microspheres for photodegradation of 4-chlorophenol

Synthesis and structure characterization of two cadmium coordination polymers based on μ₂-bridging bidentate hydrazine ligand