Electrochemical determination of levetiracetam by screen-printed based biosensors

This work shows an easy and fast electrochemical method for Levetiracetam (LEV) determination. which is a novel antiepileptic. Most of the methods used up to now for its determination required a pre-treatment of the sample. It is shown here that the developed Peroxidase based biosensors avoid this kind of drawbacks. Screen-printed carbon electrodes have been used as transducers for the Peroxidase immobilization by pyrrole electropolymerization. Experimental variables that can affect LEV chronoamperometric response, such as hydrogen peroxide concentration. pH and applied potential, have been optimized in order to perform a selective LEV determination. Under these conditions, the performance of the biosensors has been tested. The residual standard deviation (RSD) of the slopes of different calibration Curves was 9.77% (n=4 and alpha=0.05) for the reproducibility and 7.73% (n=4 and alpha=0.05) in the case of the repeatability. An average limit of detection of 9.81 x 10(-6) M (alpha=beta=0.05) was obtained. The biosensors have been finally applied to the determination of LEV in complex matrices, Such as pharmaceutical drugs and spiked human plasma samples, yielding Successful results. (C) 2008 Elsevier B.V. All rights reserved.