Analytical Sciences

Abstract − Analytical Sciences, 31(10), 1061 (2015).

Magnetic Enzymatic Platform for Organophosphate Pesticide Detection Using Boron-doped Diamond Electrodes
Flavio PINO,*1 Tribidasari A. IVANDINI,*2 Kazuya NAKATA,*3 Akira FUJISHIMA,*3 Arben MERKOÇI,*1,*4 and Yasuaki EINAGA*5,*6
*1 Nanobioelectronics & Biosensors Group, ICN2 - Institut Català de Nanociencia i Nanotecnologia (CERCA-CSIC-UAB), Campus UAB, Cerdanyola del Vallès, 08193 Barcelona, Spain
*2 Department of Chemistry, Faculty of Mathematics and Science, University of Indonesia, Kampus UI Depok, Jakarta 16424, Indonesia
*3 Research Institute for Science and Technology, Photocatalysis International Research Center, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
*4 ICREA, Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
*5 Department of Chemistry, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan
*6 JST-CREST/ACCEL, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan
A simple and reliable enzymatic system for organophosporus pesticide detection was successfully developed, by exploiting the synergy between the magnetic beads collection capacity and the outstanding electrochemistry property of boron-doped diamond electrodes. The determination of an organophosphate pesticide, chlorpyrifos (CPF), was performed based on the inhibition system of the enzyme acetylcholinesterase bonded to magnetic beads through a biotin-streptavidin complex system. A better sensitivity was found for a system with magnetic beads in the concentration range of 10−9 to 10−5 M. The estimated limits of detection based on IC10 (10% acetylcholinesterase (AChE) inhibition) have been detected and optimized to be 5.7 × 10−10 M CPF. Spiked samples of water of Yokohama (Japan) have been measured to validate the efficiency of the enzymatic system. The results suggested that the use of magnetic beads to immobilize biomolecules or biosensing agents is suitable to maintain the superiority of BDD electrodes.