A β2-agonist sensor based on a molecularly imprinted poly-o-phenylenediamine film on a columnar-structured platinum electrode

Abstract

A novel strategy for preparing highly sensitive molecularly imprinted sensors based on the electro-polymerization of o-phenylenediamine (o-PD) on a columnar-structured platinum (CSPt) electrode was proposed for β₂-agonist determination. The CSPt electrode was used as a working electrode to increase the specific surface area and to extend the linear range. The sensor surface morphology was characterized by scanning electron microscopy. The preparation process of the sensor was characterized by an electrochemical quartz crystal microbalance. The electrochemical performance of the sensor was investigated by electrochemical impedance spectroscopy and cyclic voltammetry. Additionally, sodium dodecyl sulfonate, which was used in the electro-polymerization reaction of o-PD, prevented the hydrolysis degradation of poly-o-phenylenediamine (PoPD) and enhanced the stability of the PoPD film in the anionic micellar media. The recognition and determination of the sensor were carried out by measuring the changes of the amperometric response of [Fe(CN)₆]^3−/4−. The proposed sensor was successfully applied to detect β₂-agonists in real human serum samples.