An efficient voltammetric platform integrating ZnS nanowires, reduced graphene oxide sheets, and ferrocene monocarboxylic acid for the sensitive detection of homocysteine.

The determination of homocysteine (HCys) has garnered significant interest within the biomedical community in recent years, as it serves as a key biomarker for a variety of diseases. Disruptions in HCys metabolism can lead to elevated blood levels of HCys, which are associated with cardiovascular diseases, Parkinson's disease, and etc. Therefore, the sensitive analysis of HCys levels in biological samples is crucial. An electrochemical method has been successfully developed for the sensitive detection of HCys using carbon paste electrodes (CPE) modified with ZnS nanowires/reduced graphene oxide sheets (ZnS NWs/rGO) nanocomposite and ferrocene monocarboxylic acid (FMC). Cyclic voltammetry (CV) results demonstrate that ZnS NWs/rGO exhibit excellent electrocatalytic activity for the oxidation of HCys at a low potential of 380 mV versus Ag/AgCl. These analytical properties, combined with the low operational potential, facilitate a reliable and sensitive determination of HCys, showing a good dynamic linearity in the range (LDR) of (0.01-10.0 µM and 10.0-90.0 µM) and a detection limit (LOD) of 0.003 µM.