Electrocatalytic Determination of Nevirapine Using a Platinum Electrode Modified with a Polymeric CoPc-Nafion-carbon nanotube Composite

Abstract

We report a Pt-modified electrode (viz. CoPc-cou-f-MWCNTs/Naf-5/Pt) fabricated by sequential drop casting of a nanoconjugate comprising a tetra-substituted coumarin cobalt phthalocyanine (CoPc-cou) and carboxylic-acid-functionalized multiwalled carbon nanotubes (f-MWCNTs), followed by immobilization of a 5% Nafion perfluorinated resin solution (Naf-5). Under optimized conditions, CoPc-cou-f-MWCNTs/Naf-5/Pt was used for the voltammetric determination of the antiretroviral drug nevirapine (NVP). The linear sweep voltammetric (LSV) response was linear from 0.6 n M to 30 μM with an estimated limit of detection (LOD) of approximately 0.2 n M, whereas the chronoamperometric response was linear over two concentration ranges. These two ranges were 4 n M to 312.5 n M (with an estimated LOD of 0.21 n M) and 2.5 μM to 30 μM. CoPc-cou-f-MWCNTs/Naf-5/Pt also showed excellent discriminatory sensing abilities toward selected organic contaminants. An average recovery of 110% was attained using the modified electrode for the LSV analysis of a spiked river-water sample, demonstrating the applicability of the modified electrode to accurate NVP analysis.