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 carbon nanotubes (MWCNTs) and zinc oxide nanoparticles (ZnONPs) to a glassy carbon (GC) electrode surface to accurately determine agmatine. The ZnONPs+MWCNTs/GC electrode surface was characterized using scanning electron microscopy and energy dispersive X-ray. Agmatine did not exhibit any peak on the GC electrode surface but exhibited a large oxidation peak at 637.9 mV on the MWCNT/GC electrode surface. Furthermore, it was observed that the electrochemical behavior of agmatine was greatly improved on the MWCNT+ZnONPs/GC electrode surface and that this surface exhibited a well-defined higher current peak at 581.9 mV. The electrochemical responses of agmatine on the MWCNT+ZnONPs/GC electrode surface were performed using square wave voltammetry. A linear plot was obtained for the current responses of agmatine against concentrations in the range of 0.1 µM–5.2 µM yielding a detection limit of 4.13×10−6 M (based on 3Sb/m). The accurate quantification of agmatine makes the ZnONPs+MWCNTs/GC electrode system of great interest for the treatment of schizophrenia.