Development of highly selective and sensitive electrochemical sensor for trace level determination of Cu2+ ions in different biological and Persian Gulf Algae samples

Abstract

Herein, a novel electrochemical sensor using carbon paste electrode (CPE) modified with synthetic Schiff base 4,4′-(2,2-dimethylpropane-1,3,diyl)-bis(azan-1-yldene)dipent-2-en-2-ol(DMPDO) and MWCNTs (DMPDO-MWCNT-CPE) was fabricated for determination of Cu²⁺ ions in different samples. The modified CPE electrode was fully characterized with SEM., cyclic voltammetry, differential pulse voltammetry, spectrophotometric analysis and experimental conditions was thoroughly studied. The electrochemical result reveals the DMPDO-MWCNT-CPE electrode exhibits excellent electrochemical performance respect to bare CPE and other construction toward Cu²⁺ ions. The fabricated nano-electrochemical sensor in 0.1 acetate buffer solution (pH 5), 12 % w of Schiff base and KCl electrolyte (0.1 mol L⁻¹) showed linear dynamic ranges 0.050–300.0 μM with detection limits (LODs) of 0.008 μ mol L⁻¹ and limit of quantitation of 0.10 μ mol L⁻¹. Also, with respect to other fabricated structures, it shows a wider dynamic range and lower LOD and LOQ values. Besides, the Cu²⁺ sensor showed strong selectivity compared to other metal ion (e.g., Al³⁺, Zn²⁺, K⁺, Mn²⁺, Ag⁺, Na⁺, Fe²⁺, Mn²⁺), high stability and excellent repeatability. The fabricated sensor was applied for to detect Cu²⁺ ions in some biological, wastewater and Persian Gulf algae samples. The results found with this method were comparable with those obtained with Flame atomic absorption spectrometry.