Zou_2025_Biosens.Bioelectron_296_118360

The extensive application of organophosphorus pesticides, coupled with their potential hazards to both food safety and human health, underscores the urgent need for reliable and sensitive point-of-care (POC) platforms for pesticide monitoring. Herein, we employ a DNA-guided strategy to synthesize Fe-based nanozymes (Fe-DNA). DNA sequence design enabled programmable regulation of Fe-DNA nanozymes, where variations in base composition and strand length precisely directed their structural evolution and catalytic performance. Among the resulting architectures, the G-rich Fe-G nanozyme exhibited favorable substrate affinity and peroxidase-like activity, providing an optimized catalytic module for biosensing. To improve the operational stability and application feasibility of the sensing platform, Fe-G was further encapsulated into a sodium alginate-based aerogel via a diffusion-hybridization method, forming a robust and portable catalytic matrix. Integrated with high-affinity acetylcholinesterase as the biorecognition element and a smartphone-assisted image-processing algorithm, the "lab in an aerogel kit" platform enabled highly sensitive and selective colorimetric detection of chlorpyrifos. The portable sensor exhibited a broad linear detection range from 3.33 to 1333.33 ng mL(-1), with a detection limit as low as 3.33 ng mL(-1). This work highlights the potential of DNA-mediated nanozyme engineering and aerogel-based solid-phase sensing architectures for the development of high-performance POC platforms.