Lanthanum cobaltite supported on graphene nanosheets for non-enzymatic electrochemical determination of catechol.

An electrochemical sensor is described for the determination of catechol (CT) based on the nanocomposite of lanthanum cobaltite supported on graphene nanosheets (LaCo/GNS). The nanocomposite was systematically examined by various analytical and spectroscopic methods. The LaCo/GNS-modified electrode exhibites good electrochemical activity towards CT determination compared to other modified and unmodified electrodes. The electrochemical signal was acquired at a redox potential of 0.21 (Epa) and 0.17 (Epc) Volt (vs. Ag/AgCl). The proposed electrode exhibits low detection limit (1.0 nM), wide working range (0.009-132 µM), and good sensitivity (5.68 µA µM-1 cm-2). The electrochemical nanoprobe has good selectivity over potentially interfering compounds. The electrochemical sensor was applied to the analysis of environmental samples with acceptable recovery. Graphical abstractSchematic representation of electrochemical determination of catechol in the environmental sample analysis using lanthanum cobaltite supported on graphene nanosheets.

Unraveling the electrochemical properties of lanthanum cobaltite decorated halloysite nanotube nanocomposite: An advanced electrocatalyst for determination of flutamide in environmental samples.

Prostate cancer is one of the primary causes of death around the world. As an important drug, flutamide has been used in the clinical diagnosis of prostate cancer. However, the over dosage and improper discharge of flutamide could affect the living organism. Thus, it necessary to develop the sensor for detection of flutamide with highly sensitivity. In this paper, we report the synthesis of lanthanum cobaltite decorated halloysite nanotube (LCO/HNT) nanocomposite prepared by a facile method and evaluated for selective reduction of flutamide. The as-prepared LCO/HNT nanocomposite shows the best catalytic performance towards detection of flutamide, when compared to other bare and modified electrodes. The good electrochemical performance of the LCO/HNT nanocomposite modified electrode is ascribed to abundant active sites, large specific surface area and their synergetic effects. Furthermore, the LCO/HNT modified electrode exhibits low detection limit (0.002 µM), wide working range (0.009-145 µM) and excellent selectivity with remarkable stability. Meaningfully, the developed electrochemical sensor was applied in real environmental samples with an acceptable recovery range.

Glucose oxidase mimicking half-sandwich nickel(II) complexes of coumarin substituted N-heterocyclic carbenes as novel molecular electrocatalysts for ultrasensitive and selective determination of glucose.

Glucose oxidase mimicking nickel-based porous structures with organic anchors are developed as cheap and reliable electrochemical sensors for the quantitative detection of glucose. A series of sterically and electronically modulated, air- and moisture-stable half-sandwich nickel(II) NHC complexes were prepared and characterized. Under the optimized electrocatalytic conditions, the nickel complex immobilized glassy carbon electrodes (GCEs) displayed high sensitivity (0.663, 1.280, 1.990 and 0.182 µA/µM) towards glucose detection, which is much higher than that of 3D porous nickel networks. The limit of detection of modified GCEs is found in the range 1.56-2.09 µM with much wider linear sensing range, and having a catalytic rate constant of 0.273 × 103 M-1s-1. Finally, the selectivity of the modified GCEs towards glucose in presence of other blood constituents was also evaluated.