Search

AbstractLevofloxacin is an antibiotic used to treat bacterial infections. This work aimed to produce a new modified electrode for the determination of levofloxacin. The graphene nanoribbons (GNRs) were prepared by chemical oxidation and a layered double hydroxide (LDH) containing nickel and cobalt cations (Ni/Co–LDH) using electrodeposition. The oxidation peak current of levofloxacin showed an increase and shifted to lower potentials using a glassy carbon electrode modified with GNRs and Ni/Co–LDH. The reported electrode demonstrated a linear dynamic range from 5.0 to 150.0 μmol L−1 with a limit of detection for levofloxacin of 1.1 μmol L−1. The modified electrodes were successfully utilized for the determination of levofloxacin in urine. [ABSTRACT FROM AUTHOR]

Immobilization of microbial cells on insoluble matrix has led to the stable performance of microorganisms in the petroleum industry. A novel floating polymer with very high potential was synthesized in the factory for cell life promotion and oil degradation. The entrapped cells of the novel and indigenous crude oil degrading bacterium, Klebsiella variicola strain SKV2 were analyzed by scanning electron microscope and the gas chromatography-mass spectrometry (GC-MS) analyses for crude oil degradation. The results showed that the efficiency of the biodegradation of crude oil on the one hand and the durability and microbial stability on the other hand were different in the two types of substrates used for fixation. GC-MS analysis showed that the maximum bioremediation efficiency of crude oil by the novel and indigenous K. variicola strain SKV2 free cells was 93.3% for 3 weeks. The biodegradation of crude oil was carried out completely and unprecedentedly, and thus 71.87% of crude oil components were completely deleted in the new method including microcapsules of agar and paraffin. The bioremediation of crude oil was 44.31% for scaffolds made of polyurethane polymer, while the cells were alive for more than 6 months in these scaffolds. [ABSTRACT FROM AUTHOR]

This paper describes the development of 1-methyl-3-butylimidazolium chloride ionic liquid/cobalt hexacyanoferrate nanoparticle modified multi-walled carbon nanotubes nanocomposite paste electrode for the electrocatalytic and adsorptive stripping voltammetric and impedimetric determination of diclofenac (DIC) in real samples. The nanocomposite was prepared by a simple chemical method and was characterised by scanning electron microscopy, Fourier transform infrared spectroscopy and atomic absorption spectroscopy. Also, the electrochemical behaviours of the modified electrode and the electrocatalytic oxidation of DIC were investigated in detail by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy techniques. The kinetic parameters such as electron transfer coefficient, and apparent rate constant for the redox reaction between DIC and the modified electrode were also determined using electrochemical approaches. It was found that the modified electrode exhibited excellent electrocatalytic activity toward the oxidation of DIC, and under the optimised conditions, the linear response range and detection limit were found to be 1.0–100.0 and 0.3 μM, respectively using the differential pulse voltammetry method. The proposed method was applied for the sensitive and selective determination of diclofenac in the urine samples and pharmaceutical formulations with satisfactory results. [ABSTRACT FROM AUTHOR]