1 research outputs found
Electrochromic Molecular Imprinting Sensor for Visual and Smartphone-Based Detections
Electrochromic
effect and molecularly imprinted technology have
been used to develop a sensitive and selective electrochromic sensor.
The polymeric matrices obtained using the imprinting technology are
robust molecular recognition elements and have the potential to mimic
natural recognition entities with very high selectivity. The electrochromic
behavior of iridium oxide nanoparticles (IrOx NPs) as physicochemical
transducer together with a molecularly imprinted polymer (MIP) as
recognition layer resulted in a fast and efficient translation of
the detection event. The sensor was fabricated using screen-printing
technology with indium tin oxide as a transparent working electrode;
IrOx NPs where electrodeposited onto the electrode followed by thermal
polymerization of polypyrrole in the presence of the analyte (chlorpyrifos).
Two different approaches were used to detect and quantify the pesticide:
direct visual detection and smartphone imaging. Application of different
oxidation potentials for 10 s resulted in color changes directly related
to the concentration of the analyte. For smartphone imaging, at fixed
potential, the concentration of the analyte was dependent on the color
intensity of the electrode. The electrochromic sensor detects a highly
toxic compound (chlorpyrifos) with a 100 fM and 1 mM dynamic range.
So far, to the best of our knowledge, this is the first work where
an electrochromic MIP sensor uses the electrochromic properties of
IrOx to detect a certain analyte with high selectivity and sensitivity