Label-free ultrasensitive electrochemical dopamine sensor fabrication using a low-cost pencil graphite electrode

A novel and label-free electrochemical sensing strategy was explored for designing the ultra-low-level dopamine sensor based on a low-cost pencil graphite electrode (PGE). Electrochemical measurements of the PG electrode towards dopamine detection were performed using the anodic sweeping voltammetry (ASV) technique with optimized deposition voltage and time. With a sensitivity of 0.022 μA nM−1 cm−2, the PG electrode demonstrated sufficient potential for highly selective detection of dopamine down to 26.5 nM concentration in the presence of other interfering bioanalytes.