Poly(methylene green) – Ethaline deep eutectic solvent / Fe2O3 nanoparticle modified electrode electrochemical sensor for the antibiotic dapsone

Abstract

A novel electrochemical sensor for dapsone has been developed comprising a poly(methylene green) film prepared by electropolymerisation, with potential cycling, on Fe2O3 magnetic nanoparticle modified electrodes in sulphuric acid-doped ethaline deep eutectic solvent. Differential pulse voltammetry, cyclic voltammetry, and scanning electron microscopy were used to characterise the system. Modified electrode architectures with different Fe2O3NP loadings were tested, with polymer films electrodeposited in ethaline-H2SO4 or H2SO4 aqueous solution. The best sensing modified electrode platform exhibited a linear response to dapsone from 0.5 to 20 μM, with a detection limit of 0.33 μM, one of the lowest values achieved. Experimental reproducibility and long-term stability were excellent. Quantitative measurement of dapsone in pharmaceutical tablets and in river water was successful with excellent recoveries.