Electrochemical Analysis of Evans Blue by Surfactant Modified Carbon Nanotube Paste Electrode

Electrochemical sensor for the specific and sensitive detection of Evans blue (EB) at physiological pH in 0.2M phosphate buffer solution (PBS) was developed by the surface modification using Triton X -100 (TX-100) surfactant. The cyclic voltammetry (CV) studies show enhanced peak separation, appreciable sensitivity, selectivity and stability which allowed this TX-100 surfactant modified carbon nanotube paste electrode (TX-100MCNTPE) to analyse EB individually and simultaneously along with tartrazine (TZ) in the potential range of 0.2 V to 0.7 V. The electrode morphology was characterised by field emission scanning electron microscopy (FESEM). The oxidation potential of EB shifted negatively, and enhanced irreversible oxidation peak current was observed at 0.505V which served as the analytical response. In the prime condition, the anodic peak current of EB increased linearly, and two linear ranges were observed from 10 μM to 100 μM with the limit of detection (LOD) of 5.06 μM and limit of quantification (LOQ) of 16.87 μM. Scan rate studies reveal that the entire process in the electrode surface is adsorption controlled. The modified electrode showed excellent reproducibility, repeatability and antifouling properties.