A novel Pd-Fe3O4/PEDOT:PSS/nitrogen and sulfur doped-Ti3C2Tx frameworks as highly sensitive sensing platform toward parathion-methyl residue in nature

Excessive pesticide residues (e.g., parathion-methyl, PM) not only threaten human health but also cause serious environmental pollution. Herein, a palladium-magnetic iron/poly(3, 4-ethylenedioxythiophene):poly(styrenesulfonic acid)/nitrogen and sulfur co-doped titanium carbide (Pd-Fe3O4/PEDOT:PSS/NS-Ti3C2Tx) composite frameworks was fabricated, hoping to provide an interesting strategy for the design of PM sensor. First, the NS-Ti3C2Tx was synthesized through N and S co-doped modification of Ti3C2Tx to improve its electrical properties. The hierarchical PEDOT:PSS/NS-Ti3C2Tx composite, as catalytic supports of Pd-Fe3O4, was constructed with PEDOT:PSS inserting between the NS-Ti3C2Tx nanolayers to enhance the dispersibility and continuity of the layers. The components and structure of composites were well identified by various characterization and analysis methods. More importantly, the Pd-Fe3O4/PEDOT:PSS/NS-Ti3C2Tx/GCE sensing platform indicates an outstanding electrocatalytic activity in the electro-reduction of PM with sensitivity of 517.08 mu A mM(-1) cm(-2), linear detection range of 0.01-140 mu M, limit of detection as 3.3 nM, and k(s) as 3.585 s(-1). Moreover, this sensing platform was successfully applied to PM residue detection in vegetable, surface water and soil, showing high accuracy and promising feasibility in application. (c) 2022 Elsevier Ltd. All rights reserved.