New and sensitive sensor for voltammetry determination of Methamphetamine in biological samples

An electrochemical sensor was developed for determining ethamphetamine (MA) using glassy carbon electrode (GCE) modified with amine functionalized multi-walled carbon nanotube (MWCNT-NH2) and gold nanoparticles (Au-NPs) linked to nanomagnetic core shells (Fe3O4@SiO2-Si-(CH2)3-SH). Cyclic voltammetry (CV) shows that at GCE Methamphetamine has a very weak irreversible oxidation peak at about 0.80 V, but after modification of the GCE the anodic peak current increased significantly. The mechanism involve the equal number of electrons and protons. The oxidation peak mechanism was controlled via diffusion. Square-wave voltammetry (SWV) has been used as a very sensitive method for measuring MA under optimal conditions. The developed sensor, has an acceptable analytical performance in terms of linearity from 5.0 × 10− 8 to 5.0 × 10− 5 mol L− 1 (R2 = 0.999) with the detection limit 16 nM. Standard addition method was used for determination of MA in human urine.