Efficacious Detection of Epinephrine in the Midst of an Interference (ASCORBIC ACID) Employing Designed Gold Electrode with Cobalt Octacarboxyphenoxy Phthalocyanines

The modification of gold electrode with cobalt octacarboxyphenoxy phthalocyanines (CoOcPhOPc), for the pH selective detection of epinephrine was investigated. 1,4-phenylene diamine dihydrochloride (PA) was electrografted onto gold electrode and CoOcPhOPc was immobilized on the electrode via amide bond coupling. The modified electrode (Au-PA-CoOcPhOPc) was characterized with voltammetry and impedance studies. The modified electrode demonstrated high sensitivity and good selectivity with low limit of detection (LOD) of 0.27 nM at 3σ, limit of quantitation (LOQ) of 0.9 nM at 10σ and high sensitivity of 0.6 ± 0.01 nA nM-1 towards the detection of epinephrine (EP). The reusability, stability and reproducibility of the electrode were confirmed for the detection with cyclic voltammetry (CV). The calibration curves showed very good and strong positive linear relationship with correlation coeffient of +0.99. The calibration curve of the square root of the scan rate confirmed the detection and the process of the reaction to be diffusion controlled.