An amperometric l-tryptophan sensor platform based on electrospun tricobalt tetroxide nanoparticles decorated carbon nanofibers

•Co3O4-CNF were prepared by electrospinning technology followed by successive annealing process and oxidation process.•Morphology and catalytic property of different weight percentage of cobalt acetate in precursor were studied.•The proposed sensor has good stability and reproducibility.

A glassy carbon electrode (GCE) modified with electropun tricobalt tetroxide nanoparticles decorated carbon nanofibers (Co3O4-CNF) were first applied for the determination of l-tryptophan (l-Trp). The synthesized Co3O4-CNF was characterized by scanning electron microscopy, Raman, X-ray diffraction and electrochemical impedance spectroscopy. The electrochemical detection of l-try was successfully conducted in 0.1 M phosphate solution (pH 2). The linear relationship of l-Trp was in the range of 0.005–40 μM and the detection limit reached 0.002 μM (S/N = 3) with little interference from other amino acids.