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

Abstract

A simple strategy for determination of tryptophan (TRP) based on Fe3O4@SiO2/GO nano-composite 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 electroche-mical 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 prac-tical application of the modified electrode was demonstrated by measuring the concen-tration of tryptophan in real samples.