Electrochemical Determination of Homocysteine Using Self-Assembled 6-Ferrocenylhexanethiol on a Molybdenum Disulfide Nanoparticle Modified Glassy Carbon Electrode (GCE)

Abstract

The determination of homocysteine (Hcy) is important because high levels are associated with a greater risk of developing heart disease or stroke. Herein, an electrochemical sensor of homocysteine was constructed based upon the self-assembly of 6-ferrocenylhexanethiol (FcC₆SH) on a MoS₂ nanoparticles-modified electrode with a Nafion coating. The sensor showed a favorable electrocatalytic activity for oxidation of homocysteine since 6-ferrocenylhexanethiol acted as a good electron transfer mediator. Moreover, the MoS₂ nanoparticles served as modifiers to covalently immobilize FcC₆SH and enhance the electrochemical active surface area. Highly sensitive determination of homocysteine was achieved with a linear range from 2.0 to 100 µmol L⁻¹ and a minimum detectable concentration of 0.30 µmol L⁻¹ by chronoamperometry. The constructed sensor was applied to the analysis of immunoglobulin G (IgG) samples with satisfactory results.