A Novel Superoxide Anion Biosensor for Monitoring Reactive Species of Oxygen Released by Cancer Cells

Abstract

In this study, novel sensitive and selective hydrogel microstructures to detect superoxide anions released by cancer cells, based on electrochemical biosensors, are proposed. Ferrocene was coupled with superoxide dismutase within a poly(ethylene glycol) diacrylate hydrogel matrix. The pre-polymer solution was patterned by photolithography in gold microelectrodes fabricated on top of glass slides. The biosensor was characterized by electrochemical impedance spectroscopy and cyclic voltammetry, and was able to detect superoxide anions in a wide linear range from 5 to 100 μM, with a low detection limit of 0.001 μM and sensitivity of 14.1 nA μM/mm2. Moreover, the biosensor was able to directly detect reactive oxygen species released from prostate cells. Furthermore, the reproducibility, stability and selectivity of the biosensor achieved better results when compared with the previous report, so this methodology can be used in physiological and pathological detection of reactive oxygen species, providing a powerful platform for clinical diagnostics in the future.