Development of an amperometric sensor for phenol compounds using a Nafion® membrane doped with copper dipyridyl complex as a biomimetic catalyst

The use of [CuDipyCl2] as a biomimetic catalyst in the construction of an amperometric enzymeless biosensor for phenol determinations is reported. The sensor was prepared modifying a glassy carbon electrode with a Nafion® membrane doped with [CuDipyCl2]. The sensor presented a higher response for dopamine in 0.1 mol l−1 phosphate buffer at pH 7, with an applied potential of −50 mV versus SCE. With the optimized operational conditions a linear response range between 4.0×10−5 and 6.0×10−4 mol l−1, with a sensitivity of 350±10 nA l mmol−1 cm−2 and a detection limit of 9.0×10−6 mol l−1 were observed for the sensor. The response time presented for this sensor was approximately 1 s, presenting the same response for at least 50 measurements, with good repeatability (R.S.D. 3.8%, for n=9). The difference of the response between four preparations was 7%. Detailed investigations of the sensor response for monophenol and diphenol compounds and interfering species were carried out.