Microfabricated interdigitated Au electrode for voltammetric determination of lead and cadmium in Chinese mitten crab (Eriocheir sinensis)

An in-situ plating bismuth modified interdigitated Au electrode (IAE) was developed for determination of Pb2+ and Cd2+ in crab. The IAE was fabricated and used as counter electrode and working electrode. Cyclic voltammetry (CV) was performed with the IAE for studying electrochemical performance, showing clear redox peaks. The key operational parameters were optimized, which were 600 μg L−1 of Bi3+ concentration, 0.1 mol L−1 of acetate buffer (pH 4.5), −1.2 V of deposition potential and 180 s of deposition time. Under optimized condition, the linear range of IAE was from 5 to 50 μg L−1 for both metal ions, with detection limit (threefold signal-to-noise) of 0.74 μg L−1 for Pb2+ and 0.86 μg L−1 for Cd2+. Finally, the developed sensor was applied to detect Pb2+ and Cd2+ in crab extract solutions by standard addition method. The results were in good agreement with outcomes obtained by inductively coupled plasma mass spectrometry.