Sodium Dodecyl Sulfate Modified Carbon Nano Tube Paste Electrode for Sensitive Cyclic Voltammetry Determination of Isatin

Purpose: Isatin (IS) is a synthetically significant heterocyclic moiety with an influential pharmacodynamic indole nucleus and hence the electrocatalytic property of has been investigated. Methods: The electrochemical analysis was demonstrated by cyclic voltammetry (CV) in the potential window of 0.2 V to 1.4 V using sodium dodecyl sulfate (SDS) modified carbon nano tube paste electrode (SDSMCNTPE) over a pH range of 6 to 8.5 in 0.2 M phosphate buffer solution (PBS). Surface morphology was studied by using Field emission-scanning electron microscopy (FESEM). Results: The CV study discloses that under ideal condition oxidation of IS arises at a potential of 0.970 V accompanied with an exceptional stability, selectivity and sensitivity for the resultant SDSMCNTPE contrasting to bare carbon nano tube paste electrode (BCNTPE). Individual parameters like electrode surface area, effect of surfactant, detection limit, simultaneous detection of IS and resorcinol (RC) were studied at a scan rate of 0.1 V/s. Scan rate study uncovers the process is diffusion controlled. The oxidation peak current amplified linearly with the surge in concentration of IS under ideal condition. Detection limit (LOD) and limit of quantification (LOQ) in the solution of optimum pH (7.5) at a scan rate of 0.100V/s is 2.4x10(-7) M and 8.2 x 10(-7) M respectively. Conclusion: The proposed electrode portrays excellent repeatability, reproducibility and reliability to resistant electrode fouling.

Automated summary

The study successfully demonstrated the oxidation of IS using SDS modified carbon nano tube paste electrode, showing superior stability, selectivity, and sensitivity compared to bare carbon nano tube paste electrode. The process was found to be diffusion controlled and linearly increased with the concentration of IS.