Multimodal electrochemical and SERS platform for chlorfenapyr detection

Abstract Multimodal sensors combining different detection methodologies on a single platform can provide complementary information for the detection of analytes. Here we developed a novel inexpensive metallic substrate that can be used for dual functional sensing via ElectroChemistry (EC) and Surface Enhanced Raman Spectroscopy (SERS). We demonstrated the utility of this platform for the detection of chlorfenapyr, which is an agricultural insecticide and a toxin that disrupts respiratory pathways and proton gradients in mitochondria. Our platform is based on a commercial bimetallic glucose test strip modified with silver nanoparticles. The performance of EC and SERS was evaluated via test probes potassium ferricyanide ((K3Fe(CN)6 )) and 4-Aminothiophenol, respectively. The substrate was used as a working electrode for chlorfenapyr detection via EC and SERS. SERS allows the identification of chlorfenapyr by its characteristic peak near 2230 cm−1, with a Limit of Detection (LOD) of 7 ppm. EC allows for quantitative measurement of the analyte within the concentration range of 20–50 ppm. The EC LOD of 4.2 ppm meets residue tolerance limit in chive, according to the US Code of Federal Regulations. This platform may open up avenues towards cost-effective and portable detection of other analytes.