Sensitive determination of capsaicin in pepper samples using a voltammetric platform based on carbon nanotubes and ruthenium nanoparticles

•Carbon nanotubes were decorated with ruthenium nanoparticles.•The RuNPs/CNTs/GCE was employed for quantifying capsaicin in pepper samples.•The proposed voltammetric method achieved a LOD of 2.5 nM for capsaicin.•The RuNPs/CNTs/GCE exhibited higher sensitivity for capsaicin.•The heat intensity of peppers has been determined using the proposed electrode.

A voltammetric platform based on modifying glassy carbon electrodes (GCEs) with ruthenium nanoparticles decorated carbon nanotubes (CNTs) was applied for the determination of capsaicin in pepper samples. The nanoparticles of ruthenium (RuNPs) were obtained at carbon nanotubes modified GCE by cyclic voltammetry. The composite of RuNPs-CNTs was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The proposed voltammetric platform, RuNPs/CNTs/GCE, highly improved the voltammetric process of capsaicin in comparison to the CNTs/GCE and bare GCE. A linear concentration range was obtained from 1.0 × 10−8 to 4.1 × 10−7 M (R2 = 0.9987) with a detection limit of 2.5 × 10−9 M. The voltammetric platform has successfully been applied for quantifying capsaicin in various pepper samples including Isot. The proposed voltammetric platform offers advantages such as high sensitivity, selectivity and precision.