An amperometric biosensor for the detection of hydrogen peroxide released from human breast cancer cells

The rapid, accurate and sensitive determination of hydrogen peroxide (H2O2) is of great significance in the physiological, pathological and environmental fields. In this work, we have proposed a highly sensitive and selective amperometric biosensor for the detection of extracellular H2O2 released from human breast cancer cells with the help of a sequence-specific peptide. Since the peptide immobilized on the electrode surface can specifically bind with horseradish peroxidase (HRP) in a favorable orientation, which then well promotes the catalytic activities of the immobilized enzyme toward the reaction of o-phenylenediamine and H2O2, the proposed biosensor can detect H2O2 in a wide linear range from 1.0 x 10(-7) M to 1.0 x 10(-4) M with a low detection limit of 3.0 x 10(-8) M. It can be also directly used to efficiently trace extracellular H2O2 released from human breast cancer cells MCF-7. Furthermore, the reproducibility, stability and selectivity of the biosensor are also quite well compared with the previous report, so our biosensor might be potentially useful in physiological and pathological detection of H2O2 in the future. (C) 2012 Elsevier B.V. All rights reserved.