A Sensitive Quantification of Agmatine Using a Hybrid Electrode Based on Zinc Oxide Nanoparticles

Abstract

An electrochemical sensor was prepared by modifiying a hybrid of multi-walled carbonnanotubes (MWCNTs) and zinc oxide nanoparticles (ZnONPs) to a glassy carbon (GC) electrodesurface to accurately determine agmatine. The ZnONPs+MWCNTs/GC electrode surface wascharacterized using scanning electron microscopy (SEM) and energy dispersive X-ray (XRD).Agmatine did not exhibit any peak on the GC electrode surface, but exhibited a large oxidation peakat 637.9 mV on the MWCNTs/GC electrode surface. Furthermore, it was observed that theelectrochemical behavior of agmatine was greatly improved on the MWCNT+ZnONPs/GC electrodesurface and that this surface exhibited a well-defined higher current peak at 581.9 mV. Theelectrochemical responses of agmatine on the MWCNT+ZnONPs/GC electrode surface wereperformed using square-wave voltammetry (SWV). A linear plot was obtained for the currentresponses of agmatine against concentrations in the range of 0.1 μM–5.2 μM yielding a detectionlimit of $4.13×10−8$ M (based on $3Sb/m$). The accurate quantification of agmatine makes theZnONPs+MWCNTs/GC electrode system of great interest for the treatment of schizophrenia.