Voltammetric determination of acetaminophen and tryptophan using a graphite screen printed electrode modified with functionalized graphene oxide nanosheets within a Fe3O4@SiO2 nanocomposite

A high sensitive electrochemical nanostructure sensor based on graphene oxide/Fe3O4@SiO2 nanocomposite modified graphite screen printed electrode (GO/Fe3O4@SiO2/SPE) has been developed for trace analysis of acetaminophen. The electrochemical study of the modified electrode, as well as its efficiency for simultaneous voltammetric oxidation of acetaminophen and tryptophan is described. Compared with bare SPE the GO/Fe3O4@SiO2/SPE exhibited excellent electrocatalytic activity toward the oxidation of acetaminophen. The plot of catalytic current versus acetaminophen concentration showed a linear segment in the concentration range 0.5 to 100.0 µM. The detection limit of 0.1 µM was obtained using calibration plot. Also the anodic peaks of acetaminophen and tryptophan in their mixture can be well separated. The GO/Fe3O4@SiO2/SPE has been successfully applied and validated by analyzing acetaminophen and tryptophan in urine and pharmaceutical samples.