Application of Fe3O4@SiO2/GO nanocomposite for sensitive and selective electrochemical sensing of tryptophan

Sa？etak A simple strategy for determination of tryptophan (TRP) based on Fe3O4@SiO2/GO nanocomposite modified graphite screen printed electrode (Fe3O4@SiO2/GO/SPE) is reported. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to characterize the performance of the sensor. The Fe3O4@SiO2/GO/SPE displayed excellent electrochemical catalytic activities. The oxidation overpotentials of tryptophan decreased significantly and its oxidation peak current increased dramatically at Fe3O4@SiO2/GO/SPE. Under the optimized experimental conditions tryptophan showed linear response over the range of 1.0-400.0 μM. The lower detection limit was found to be 0.2 μM for tryptophan. The practical application of the modified electrode was demonstrated by measuring the concentration of tryptophan in real samples