A novel amperometric galactose biosensor based on galactose oxidase-poly(N-glycidylpyrrole-co-pyrrole)

A novel amperometric galactose biosensor was constructed by immobilization of galactose oxidase (GAox) onto poly(N-glycidylpyrrole-co-pyrrole) film. GAox enzyme was immobilized onto the electrochemically prepared novel conducting polymer film by direct one-step covalent attachment without using any coupling agents. The biosensor surface was characterized by FT-IR spectroscopy and atomic force microscopy (AFM). Amperometric response was measured as a function of concentration of galactose, at fixed potential of +0.7 V vs. Ag/AgCl in a phosphate buffered saline (pH 7.5). The mediated hydrogen peroxide biosensor had a fast response of less than 5 s with linear range 2–16 mM. The sensitivity of the biosensor for galactose was 1.75 μA/mM. The factors influencing on the performance of the resulting biosensor were studied in detail.

Research highlights▶ Poly(N-glycidylpyrrole-co-pyrrole) film enable direct covalent immobilization without any reagent. ▶ The biosensor seems to be simple to prepare, fast to respond, inexpensive and sensitive. ▶ The conducting polymer film used in this study is an effective platform to produce reliable biosensors.