Multifunctional Conductive Polymer Nanocomposite for Intelligent Pesticide Sensing: Trends, Challenges, and Future Prospects

Widespread use of organophosphate pesticides (OPPs) raises environmental, food safety, and public health concerns, and drives demand for rapid, sensitive, portable analytical technologies. We reviewed conductive polymer composite (CPC)-based electrochemical OPP sensors, focusing on the structure–performance relationships of representative polymers, polyaniline (PANI), polypyrrole (PPy), polythiophene (PTh), and poly(3,4-ethylenedioxythiophene) (PEDOT), and their hybrids with carbon nanomaterials, metal nanoparticles, metal oxides, MXenes, and metal–organic frameworks. We provided a critical comparison of conductive polymer systems, composite architectures, and enzymatic, molecularly imprinted polymer-based, and direct electrocatalytic sensing strategies, highlighting how material selection influences performance and applicability. Reported CPC-based sensors achieved limits of detection from micro- to femtomolar and successful application in real environmental and food samples; however, these results illustrate the capabilities achieved by selected high-performing reported platforms rather than the overall performance of CPC-based sensors. Despite these advances, reproducibility, long-term operational stability, matrix effects, sensor variability, and field implementation still limit deployment. We discussed future directions to address these challenges, including AI-assisted data analysis, standardised validation, portable field platforms, and sustainable fabrication. Rather than identifying a universally superior platform, this review emphasises rational material selection and composite design to guide CPC sensor development and translation for environmental monitoring and food safety applications.