Electrochemical Sensing of Levodopa in Presence of Tryptophan Using Modified Graphite Screen Printed Electrode with Magnetic Core-Shell Fe3O4@SiO2/GR Nanocomposite

In the present paper, Fe3O4@SiO2/GO nanocomposite was synthesized and used to modify a graphite screen-printed electrode. This modified electrode was used to determine levodopa in the presence of tryptophan. Differential pulse voltammetry data showed that the obtained anodic peak currents were linearly dependent on levodopa concentrations in a range of 0.5-800.0 mu M, with the detection limit of 0.09 mu M. This novel sensor has several advantages such as rapid response, high stability, reproducibility, and high sensitivity. In addition, this proposed sensor was used to determine levodopa and tryptophan in human blood serum and urine samples.