A nanotechnological approach to biosensors sensitivity improvement: application to organophosphorus pesticides determination

Abstract

An electrochemical organophosphorus hydrolase-based sensor for direct organophosphorus pesticides determination was developed, analytically characterized and applied for paraoxon quantification. The biosensing platform was constructed by one-step electrodeposition onto the surface of a glassy carbon electrode of a bionanocomposite of chitosan with carbon nanotube (CNTs), hydroxyapatite (HA) and organophosphorus hydrolase. The sensor, optimized with respect to the CNTs and HA load, was characterized by the application of cyclic voltammetry and chronoamperometry. The limit of detection (LOD) was found to be as low as 0.1 µmol L−1, the linear concentration range was extended up to 80 µmol L−1, and the sensitivity was as high as 5.10 nA L µmol−1. The sensor possesses enhanced sensitivity towards organophosphorus pesticides (OPs), because of the CNTs and the HA nanoparticles synergistic action.