A novel amperometric sensor for ascorbic acid based on poly(Nile blue A) and functionalised multi-walled carbon nanotube modified electrodes

► Novel sensor for ascorbic acid with multi-walled carbon nanotubes and poly(Nile blue A). ► Characterisation by cyclic voltammetry and electrochemical impedance spectroscopy. ► Ascorbate sensing by cyclic voltammetry and fixed potential amperometry. ► No interferences from components commonly found in clinical/pharmaceutical samples. ► Determination of ascorbic acid in commercial tablet samples successfully performed.