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.