Electrochemical biosensor for detection of 17 beta-estradiol using semi-conducting polymer and horseradish peroxidase

摘要

A convenient electrochemical sensing pathway for 17 beta-estradiol detection was investigated. The system is based on a conducting polymer and horseradish peroxidase (HRP) modified platinum (Pt) electrode. The miniature estradiol biosensor was developed and constructed through the immobilization of HRP in an electroactive surface of the electrode covered with electroconducting polymer - poly(4,7-bis(5-(3,4-ethylenedioxythiophene)thiophen-2-yl)benzothiadiazole). The detection strategy is based on the fact that 17 beta-estradiol (E2) and pyrocatechol (H(2)Q) are co-substrates for the HRP enzyme. HRP, which does not react with E2, in the presence of H2O2 catalyses the oxidation of H(2)Q to o-benzoquinone (Q). With the optimized conditions, such constructed biosensing system demonstrated a convenient level of sensitivity, selectivity in a broad linear range - 0.1 to 200 mu M with a detection limit of 105 nM. Furthermore, the method was successfully applied for hormone detection in the presence of potential interfering compounds (ascorbic acid, estriol, estrone, uric acid and cholesterol).