Preparation and properties of an uricase biosensor based on copolymer of o-aminophenol-aniline

An uricase biosensor of poly-o-aminophenol-aniline is firstly reported in this paper. The preparing process of the biosensor is as follows: An uricase electrode is prepared with one-step process using the copolymer of aniline and o-aminophenol, then the electrode is hydrolyzed in 6.0 mol dm−3 hydrochloric acid solution to remove the uricase that may be affected by monomer during copolymerization and a template with moderate apertures for immobilization uricase was obtained. Finally, active uricase is immobilized into the template based on doping and undoping of the copolymer, and a copolymer-uricase biosensor is obtained. Some factors that affect response current are studied, such as temperature, pH, potential and substrate concentration. The result of experiment indicates that the response current of the copolymer-uricase biosensor prepared with template process only decreases by about 19% for 50 days, but that of polyaniline-uricase biosensor prepared with two-step process decreases by approximately 43% for 40 h. FTIR, UV–vis and SEM are used to characterize the copolymer-uricase biosensor.