Receptor-Free AIEE-Conjugated Polymer Nanoparticle-Based PoC Device for Amplified Detection of Pendimethalin

Pendimethalin (PDM) is a chemically synthesized herbicide and is primarily employed to control broadleaf weeds and woody plants. It enters our environment from production industries and from human activity in farming. Pendimethalin residues in edible foodstuffs and water sources are a serious worldwide problem as they are linked to various health issues. As such, there is an urgent need for the construction of a portable point-of-care (PoC) testing device for the detection of pendimethalin residues from food and vegetables before being consumed. Considering this challenge, an aggregation-induced enhance emission (AIEE) polymer PF2CN is developed by modifying the conjugated backbone of polyfluorene-based polymer PFP. The insertion of an M2CN monomer into the conjugated backbone of PF2CN plays a key role in tuning the photophysical property of the PF2CN polymer where it shows AIEE activity with red-shifted emission. Further, the PF2CN polymer shows remarkable sensitivity and selectivity toward PDM with a limit of detection (LOD) of 2.8 nM, which is much less than the standard maximum residual limits for pesticides in food. Notably, the simultaneous occurrence of PET and FRET serves as a “receptor-free” selective sensor for PDM. Furthermore, the designed PF2CN conjugated polymer-based PDM detection process is miniaturized into a prototype smartphone device, thereby providing a rapid and practical solution for on-site toxic analyte detection, thereby providing higher environmental safety and protection.