Bilayer lipid membrane biosensor with enhanced stability for amperometric determination of hydrogen peroxide

In this paper, a polydopamine (PDA) film is electropolymerized on the surface of bilayer lipid membrane (BLM) which is immobilized with horseradish peroxidase (HRP). The coverage of the PDA film on HRP/BLM electrode is monitored by electrochemical impedance spectroscopy (EIS). The electrocatalytic reduction of H2O2 at the PDA/HRP/BLM electrode is studied by means of cyclic voltammetry (CV). The biosensor has a fast response to H2O2 of less than 5 s and an excellent linear relationship is obtained in the concentration range from 2.5 × 10−7 to 3.1 × 10−3 mol L−1, with a detection limit of 1.0 × 10−7 mol L−1 (S/N = 3). The response current of BLM/HRP/PDA biosensor retains 84% of its original response after being stored in 0.1 mol L−1 pH 7.0 PBS at 4 °C for 3 weeks. The selectivity, repeatability, and storage stability of PDA/HRP/BLM biosensor are greatly enhanced by the coverage of polydopamine film on BLM.