Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Original Papers
Ultrasensitive Biosensor for Detection of Organophosphorus Pesticides Based on a Macrocycle Complex/Carbon Nanotubes Composite and 1-Methyl-3-octylimidazolium Tetrafluoroborate as Binder Compound
Neuma das Mercês PEREIRAFernando Mota de OLIVEIRANara Rúbia PEREIRARodrigo Moreira VERLYDênio Emanuel Pires SOUTOLauro Tatsuo KUBOTAAuro Atsushi TANAKAFlavio Santos DAMOSRita de Cássia Silva LUZ
Author information

2015 Volume 31 Issue 1 Pages 29-35


This work describes the highly sensitive detection of organophosphorus pesticides employing the cobalt(II) 4,4,4,4-tetrasulfo-phthalocyanine (CoTSPc) macrocycle complex, carbon nanotubes (CNT), and 1-methyl-3-octylimidazolium tetrafluoroborate (OMIM[BF4]). The technique is based on enzyme acetylcholinesterase (AChE) inhibition. The composite was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and amperometry. The AChE was immobilized on the composite electrode surface by cross-linking with glutaraldehyde and chitosan. The synergistic action of the CoTSPc/CNT/OMIM[BF4] composite showed excellent electrocatalytic activity, with a low applied potential for the amperometric detection of thiocholine (TCh) at 0.0 V vs. Ag/AgCl. The calculated catalytic rate constant, kcat, was 3.67 × 103 mol−1 L s−1. Under the optimum conditions, the inhibition rates of these pesticides were proportional to their concentrations in the ranges of 1.0 pmol L−1 to 1.0 nmol L−1 (fenitrothion), 2.0 pmol L−1 to 8.0 nmol L−1 (dichlorvos), and 16 pmol L−1 to 5.0 nmol L−1 (malathion).

  Fullsize Image
Content from these authors
© 2015 by The Japan Society for Analytical Chemistry
Previous article Next article