Sulfur vacancy engineering enables a synergistic multisite platform for dual-functional sensing of benzimidazole...

Developing high-performance catalytic materials toward sensitive and robust pesticide quantification is still a formidable challenge in food and environmental analysis. Herein, we report the rational synthesis of sulfur-vacancy-enriched carbon material (denoted as Sv-Fe@NC) with integrated Fe-N_x, Fe₃C and Fe-S multi-component active sites via a defect-engineering-induced active-site modulation strategy. The engineered Sv facilitate the in-situ generation of varied Fe-based catalytic centers and strengthen the interfacial synergy across distinct active moieties, consequently boosting both electrocatalytic performance and enzyme-mimicking catalytic activity. Relying on the synergistic coupling of multi-site components and sulfur-vacancy defects, the as-prepared Sv-Fe@NC is exploited as a dual-functional sensing platform for the quantitative analysis of benzimidazole fungicides. Specifically, the constructed electrochemical sensor delivers a broad linear calibration range spanning 0.7 nM to 10 μM with an ultralow limit of detection (LOD) of 0.23 nM toward carbendazim (CBZ). Meanwhile, the corresponding colorimetric sensor enables sensitive quantification of thiophanate-methyl (TM), displaying a linear range of 0.3-17 μg/mL and an LOD down to 0.08 μg/mL. Furthermore, the practical applicability of this dual-functional sensing methodology is verified using real pear and grape fruit samples. This study not only deepens the fundamental understanding of sulfur-vacancy-regulated multi-component catalyst design, but also establishes a facile and feasible pathway to construct high-efficiency bifunctional sensing materials for hazardous pesticide monitoring.