Fabrication and application of a novel modified electrode based on β-cyclodextrin/ferrocenecarboxylic acid inclusion complex

A novel modified glassy carbon electrode (GC) was fabricated by including ferrocenecarboxylic acid (FcA) into the cavity of β-cyclodextrin (β-CD); meanwhile, glutaraldehyde (GA) and fresh egg white (FEW) were used as a cross-linking agent to make FcA not leak out easily. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the electrode modifying process. The modified electrode showed a good electrocatalytic activity for the oxidation of ascorbic acid (AA). The catalytic current versus its concentration had a good linearity in the range of 6.2 × 10−6 to 5.0 × 10−3 mol L−1, with a detection limit of 1.0 × 10−6 mol L−1 and a signal-to-noise ratio of 3. We obtained two separate peaks for AA and dopamine (DA) in the same solution with differential pulse voltammetry. The separation between the two peaks potential was about 199 mV.