Carbon nanotube–chitosan modified disposable pencil graphite electrode for Vitamin B₁₂ analysis

A single walled carbon nanotube–chitosan (SWCNT–chitosan) modified disposable pencil graphite electrode (PGE) was used in this study for the electrochemical detection of Vitamin B₁₂. Electrochemical behaviors of SWCNT–chitosan PGE and chitosan modified PGE were compared by using cyclic voltammetry (CV), square-wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) techniques. SWCNT–chitosan modified electrode was also used for the quantification of Vitamin B₁₂ in pharmaceutical products. The results show that this electrode system is suitable for sensitive Vitamin B₁₂ analysis giving good recovery results. The surface morphologies of the SWCNT–chitosan PGE, chitosan modified PGE and unmodified PGE were characterized by using scanning electron microscopy (SEM).