Impedimetric sensor based on the integration of porous nanomaterials and conductive polymers
Jimena S Tuninetti, Luciano D. Sappia, Marcelo Ceolín, Wolfgang Knoll, Matías Rafti,
and Omar Azzaroni
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas- Universidad Nacional de La Plata- Consejo Nacional de Investigaciones Científicas y Técnicas (INIFTA-UNLP-CONICET)
Abstract: The development of new methods for the detection and removal of pesticide residues in agricultural products is a research topic of great importance worldwide. Among them, imazalil (a widely used post-harvest fungicide) stands out for its effectiveness in citrus. In this work, a composite film for the impedimetric sensing of imazalil built from metal-organic framework nanocrystallites homogeneously distributed on a conductive poly(3,4-ethylene dioxythiophene) (PEDOT) layer is presented. The as-synthetized thin films are produced via spin-coating over poly(ethylene terephtalate (PET) substrate following a straightforward, cost-effective, single-step procedure. By means of impedance spectroscopy, the electric transport properties of the films are elucidated, and high sensitivity towards IMZ concentration in the range of 15 ppb to 1 ppm is demonstrated (featuring 1.6 and 4.2 ppb limit of detection, when using signal modulus and phase, respectively).