Zerovalent Nano Iron Electrochemical Sensor for the Determination of Ascorbic Acid in Presence of Dopamine using Sodium Dodecyl Sulphate

An important electro-chemical sensor was developed for the simultaneous determination of biologically electro-active compounds like ascorbic acid (AA) and dopamine (DA) which coexist in the body as an extra-cellular fluid with high oxidation potentials. Zerovalent nano iron (ZVNI) particles were synthesized by chemical method and the same particles were incorporated into a carbon paste electrode. ZVNI/ZVNISDS modified electrode was characterized by using electro-analytical techniques like SEM, cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques in 1 mM AA with 0.1 M PBS (pH 7.0) at a scan rate of 50 mVs-1. This chemically modified electrode showed a fivefold enhancement in the oxidation peak current when compared to the bare carbon paste electrode (BCPE). Scan rate was linearly proportional to the anodic peak current with a correlation coefficient of 0.9932 indicating that it is a diffusion controlled reaction. The oxidation peak current obtained for AA and DA with a linear range of 0.01 mM to 0.06 mM and 0.01 μM to 0.08 mM with a correlation coefficient of 0.9955 and 0.99562 respectively. The interference of AA and DA was successfully separated into two well resolved peaks with a potential difference of 0.0863 by using the ZVNI modified electrode. So, the proposed electro-chemical method was used to analyze the AA in clinical and pharmaceutical samples. The developed method was successfully evaluated with analytical merits like detection level, fast response, sensitivity, selectivity, stability, reproducibility and reliability.