Preparation of biosensors based in a siloxane homopolymer with interacting ferrocenes for the amperometric detection of peroxides

An amperometric enzyme electrode employing horseradish peroxidase (HRP) immobilized on a ferrocene containing polymer electrochemically deposited onto a Pt electrode is used for the determination of hydrogen peroxide and organic peroxides. The polymer consists on a siloxane-based homopolymer with pendant dendritic wedges possessing electronically communicated ferrocenyl moieties. The steady-state amperometric response of the sensors is investigated as a function of the applied potential, substrate concentration and polymer film thickness. The effects of interferences and storage on the response were also studied. The new biosensors respond to substrates at a work potential value of −50 mV (versus SCE) and show a good linear response region and protection from interferences. Moreover, their sensitivity and detection limits are competitive with other peroxides based electrodes reported.