A highly robust enzyme immobilization platform has been fabricated for electrochemical biosensors by synergistically using bio-mimetic dopamine polymer film and nanogold particles. Taking horseradish peroxidase (HRP) as an enzyme model, this presented platform has been successfully exploited to develop a novel electrochemical enzyme sensor for the detection of H2O2. Experimental results show that the nanocomposite matrix can allow HRP to be immobilized with high loading amount and well-retained bioactivity. Moreover, it can achieve rapid electron transferring between the enzyme’s active sites and the electrode surface, facilitating quick electroanalysis of H2O2. In addition, compared with other polymer materials (i.e., chitosan), the as-proposed biosensor design using the bio-mimetic dopamine polymer can show much better analytical performances. The developed enzyme sensor can allow for the detection of H2O2 with linear concentration range of 4.0×10－7～4.5×10－4 mol•L－1, detection limit of 3.7×10－7 mol• L－1 and sensitivity of 100.2 μA•L•mmol－1. High detection reproducibility, storage stability and good interference-against ability can be additionally expected.

Key words: bionic polydopamine film, gold nanoparticle, biomolecule immobilization platform, electrochemical enzyme sensor