Sensitive electrochemical determination of ethambutol in pharmaceutical formulation and human urine at nickel nanoparticles/electrochemically reduced graphene oxide modified electrode

Abstract

This paper describes the application of nickel nanoparticles decorated electrochemically reduced graphene oxide modified glassy carbon electrode (NiNPs/ERGO/GCE) for the determination of ethambutol (ETB), an anti-Mycobacterium tuberculosis drug. The modified electrode showed remarkable electrocatalytic properties accompanied with a significant enhancement in the peak current response towards ETB compared to the bare electrode. The results showed that the composite modified electrode played a significant catalytic role due to the synergetic effect of NiNPs and ERGO. The NiNPs/ERGO modified electrode demonstrated excellent square wave voltammetric response towards ETB determination at the NiNPs/ERGO/GCE in the range 0.05‒100 μM. The sensor demonstrated outstanding sensitivity towards ETB determination with limit of detection (LOD) and limit of quantification (LOQ) of 0.023 and 0.075 μM, respectively. The developed sensor was effectively validated for real sample study using drug formulation and urine samples which showed an acceptable recovery (99.6‒109%). The electrode also exhibited good precision (RSD < 1%, n = 20), reproducibility (RSD < 1.9%, n = 3), long-term stability (92% of its initial response after two weeks) and selectivity towards interfering substances in the determination of ethambutol.