Poly 3,4-ethylenedioxythiophene as an entrapment support for amperometric enzyme sensor

Abstract

International audienceA conducting polymer of poly 3,4-ethylenedioxythiophene (PEDT) was used as a matrix for entrapment of enzymes onto a platinum electrode surface in order to construct amperometric biosensors. Glucose oxidase (GOD) was used as an example, and it was entrapped in the polymer during the electrochemical polymerization. Glucose in oxygenated solutions was tested by amperometric measurements at +650 mV (vs. SCE) in a batch system. The influence of several experimental parameters in the electropolymerization process was explored to optimize the analytical performance. The detection limit and sensitivity for this biosensor were 4×10−5 M and 15.2 mA M−1cm−2, respectively. A linear range of response was found from 0.2 to 8 mM of glucose. The response time was 2–5 s. The stability of the electropolymerized films was evaluated in operational conditions. The glucose probe, stored in buffer at 4 °C when not in use, showed a residual activity of 40% after about 1 month. Glucose in synthetic serum was determined under flow injection conditions using an amperometric flow cell

Amperometric tyrosinase based biosensor using an electrogenerated polythiophene film as an entrapment support

“…An optimal pH of 6.2 was used: the same pH had previously been used for PEDT electropolymerisation [17]. Working pH, corresponding to the amperometric response of the PEDT/PPO electrode to catechol 5 μM was also investigated for pHs ranging from 5 to 8 in 0.1 M phosphate buffer solution (Figure 4).…”

Amperometric Enzyme-based Biosensors for Lowering the Interferences

“…On electrooxidation, a radical cation of EDOT is produced which is transformed to a polymeric species via several followup reactions. However, the anodic current at higher potential (0.9-1.2 V) decreased with the cycle number, because the high potential may result in the partial degradation (Fabiano et al, 2002) or overoxidation of PEDOT film. In the 15 th to 20 th cycles, the CVs of polymerization were almost the same and this implies that the polymer film was not growing due to the resistance of polymer film.…”

“…They all show that the PEDOT is a suitable material for electrochemical biosensor, so it was mainly acted as the matrix to entrap the enzyme in the studies. According to the literatures, PEDOT film not only can entrap glucose oxidase (Fabiano et al, 2002;Nien et al, 2006) or polyphenol oxidase (Vedrine et al, 2003) to fabricate a specific biosensor, but also detect single strand DNA directly (Krishnamoorthy et al, 2004). In this chapter, two systems were reviewed to cover a good interference-independent glucose biosensor.…”

Immobilization of Glucose Oxidase on Modified-Carbon-Paste-Electrodes for Microfuel Cell

“…In this study [15] the polyaniline was synthesized using 1.0 M H 2 SO 4 . Fabiano et al [16] stated that the charge numbers of the polymer surface would affect the optimal pH of enzyme activity.…”