Potentiometric urea biosensor based on urease immobilized by an electrosynthesized poly(o-phenylenediamine) film with buffering capability
2011; Elsevier BV; Volume: 157; Issue: 1 Linguagem: Inglês
10.1016/j.snb.2011.03.051
ISSN1873-3077
AutoresDaniela Chirizzi, Cosimino Malitesta,
Tópico(s)Conducting polymers and applications
ResumoA simple and novel potentiometric biosensor for urea detection was prepared by employing an electrosynthesized polymer with buffering capability. It was obtained by deposition of a weighed amount of urease (Ur) at a glassy carbon (GC) electrode followed by immobilization by an electrosynthesized poly-o-phenylenediamine (PPD) film. An unconventional “upside-down” (UD) geometry was employed for the electrochemical cell. The response of GC/Ur/PPD sensor is linear with urea concentration in the range 10 μM to 1 mM (15 mV/mM, R2 = 0.9999) due to buffering capability of PPD film, which represents a novel role of electrosynthesized polymers in their application to biosensors. At higher concentrations, the more common Nernstian response (28 mV/decade, R2 = 0.9987) is observed. The sensor exhibits a sufficient sensitivity for practical determinations, rapid response and long term stability.
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