Sensitive electrochemical detection of superoxide anion using gold nanoparticles distributed poly(methyl methacrylate)–polyaniline core–shell electrospun composite electrode

Abstract

In the present communication, a novel composite nanofibrous electrode is developed for the detection of superoxide anion (O₂˙⁻) in phosphate buffered saline (PBS). The composite fiber electrode is fabricated by dispersing gold nanoparticles onto poly(methyl methacrylate) (PMMA)–polyaniline (PANI) core–shell electrospun nanofibers. The constructed architecture is proven to be a favorable environment for the immobilization of the enzyme, superoxide dismutase (SOD). Direct electron transfer is achieved between SOD and the electrode with an electron transfer rate constant of 8.93 s⁻¹. At an applied potential of +300 mV, PMMA/PANI–Au_nano/SOD–ESCFM shows highly sensitive detection of O₂˙⁻. In addition to this, quantification of different activities of SOD is realized at PMMA/PANI–Au_nano/SOD–ESCFM. These analytical features offer great potential for construction of the third-generation O₂˙⁻ biosensor.