Bark Extract of Lantana camara in 1M HCl as Green Corrosion Inhibitor for Mild Steel

Lantana camara, an invasive species that adversely affects habitant, bioregions and environment has been studied as corrosion inhibitor. Methanolic extract of barks of Lantana camara in 1 M hydrochloric acid was tested as corrosion inhibitor on mild steel using potentiodynamic polarization technique. The corrosion inhibition efficiency of extract varied with concentration of extract and immersion of time. The inhibition was found to increase with increase in concentration of the extract. The polarization behavior of mild steel revealed that maximum inhibition efficiency is 97.33 % and 89.93 % respectively in the 1000 and 200 ppm concentration of the inhibitor respectively. The results showed that the extract of the barks of Lantana camara served as a mixed type inhibitor

Preparation of an Amperometric Glucose Biosensor on Polyaniline-Coated Graphite

Control of glucose concentration has tremendous significance in medical diagnosis, pharmaceuticals, food, and fermentation industries. Herein, we report on the fabrication of a facile, low-cost, and sensitive enzyme-based amperometric sensor using the electrochemically deposited polyaniline (PANI) film on a graphite electrode. PANI was deposited from an aqueous solution of 0.2 M aniline in 1.0 M hydrocholoric acid (HCl) by cyclic voltammetry (CV). Surface morphology and composition characterization of the PANI film were carried out by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared (FTIR) spectroscopy. Potentiostatic immobilization of glucose oxidase (GOX) enzyme in the PANI film was carried out at 0.75 V to fabricate an amperometric glucose biosensor (GOx/PANI/graphite biosensor). The glucose concentration response of the prepared sensor was studied amperometrically by detecting hydrogen peroxide (H2O2). The detection of H2O2 was optimized by calibrating the effects of pH, reduction potential, and background current. A reduction potential of -0.4 V at pH 6 was the best combination to get a maximum amperometric response of the GOx/PANI/graphite biosensor. A stable current response was obtained in 4 min with a high reproducibility in linearity within the concentration range of 0.01 M-0.1 M D-glucose. Therefore, the fabricated GOx/PANI/graphite biosensor could be a promising candidate for glucose sensing

Trace level monitoring of Cu(II) ion using CuS particles based membrane electrochemical sensor

Cu(II) monitoring is a matter of great interest to researchers due to its toxicity and adverse environmental effects. Among different methods for detecting Cu(II), ion-selective electrode (ISE) is more advantageous as they are low-cost, easy to fabricate, and highly selective. Here, we report a simple, inexpensive, and reproducible procedure for the fabrication of Cu(II) ion-selective electrodes using CuS particles and polyvinyl chloride (PVC) as a matrix. CuS particles, obtained by chemical precipitation, were characterized using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, ultraviolet-visible spectroscopy (UV-Vis), scanning electron microscopy (SEM), and energy-dispersive X-Ray spectroscopy (EDX). Optimization of the membrane compositions was done to get a well-behaved sensor by varying amounts of CuS, PVC, and acetophenone (AP). A membrane composition of 0.4 g CuS, 0.5 g PVC, and 1.0 mL AP in 5.0 mL tetrahydrofuran (THF) gave a Nernstian slope of 27.31 mV per decade change of Cu(II) ion over a wide range of concentration down to 64 ppb (1 × 10−6 M). The sensor gave a fast response time of 25 s, and it indicated the endpoint in a potentiometric titration of Cu(II) with standard EDTA solution. A pH-independent potential response was obtained in the pH 4.0–6.0