Nanozyme fabrication based on magnetic COFs and gold nanorods and its SERS detection of zearalenone.

Abstract

As one of the most common mycotoxins, Zearalenone (ZEN) not only contaminates cereal crops but also exists in processed grain products for its chemical stability. After entering human body through the food chain, ZEN exhibits remarkable bioaccumulation properties, which poses varying degrees of harmful effects to human health. The traditional chromatography instrumental methods require expensive equipment and complex experimental procedures. The aim of this manuscript is to develop a facile and accurate method for ZEN detection in food samples. Here, a SERS platform was developed for ZEN detection using COF and noble metal nanomaterial with nitroreductase (NTR)-like activity. First, magnetic COF loaded with gold nanoparticles (MCOF-Au) were synthesized as SERS enhancement substrates with partial NTR activity. Simultaneously, palladium-loaded dumbbell-shaped gold nanorods (AuNR/Pd) were prepared and served as the primary NTR in the 4-NTP/NaBH4 system, significantly enhancing both catalytic activity and SERS signal. After nucleic acid functionalization, the two components assembled. The addition of ZEN regulated the assemble of AuNR/Pd on MCOF-Au. Following magnetic separation, the catalytic and SERS activities changed in the precipitate. Using the Raman peak of the output product 4-ATP at 390 cm-1 as the quantitative marker, the method showed a linear range in 0.001 μg/kg-1000 μg/kg. The LOD was calculated as 1.88 × 10-4 μg/kg, and spiked recoveries in wheat flour and corn ranged from 88.91% to 115.78%, demonstrating high sensitivity and reliability for real-sample detection. This aptasensor integrates the high sensitivity of Raman signals with the selectivity of aptamers, providing a robust and efficient tool for accurate ZEN detection in food. COF based nanocomposites are proved to have remarkable NTR activity and the catalytic product 4-ATP exhibits prominent Raman signal, making it suitable for quantitative detectio