摘要
To address the significant threat of aflatoxin B1(AFB1)contamination to global food safety,this study innovatively developed a fluorescent aptasensor by synergistically integrating Y-shaped DNA nanostructures with the CRISPR-Cas12a system.The sensor employs an AFB1-specific aptamer(Apt)as a molecular switch,triggering a cascade signal amplification mechanism upon target binding:(1)a strand displacement reactions(SDR)generates Y-shaped DNA assemblies enriched with activation sequence,which precisely activate Cas12a′s transcleavage activity to fragment FAM-labeled signal probes(FAM-sDNA);(2)magnetic beads(MBs)separation enables efficient enrichment of target complexes,while graphene oxide(GO)suppresses background signals via π-π stacking adsorption of un-cleaved probes.Under optimized conditions,the sensor demonstrated a broad linear range(0.05-500 ng/mL,R^(2)=0.995)with an ultralow detection limit of 0.022 ng/mL.Spike-and-recovery tests in complex food matrices(peanuts,corn flour et al.)yielded recoveries of 88.96%-113.55%and relative standard deviations(RSD)below 10%.The t-test confirmed no significant difference between the sensor results and high-performance liquid chromatography(HPLC)measurements.The platform exhibits high sensitivity,specificity(against Aflatoxin G1,Fumonisin B1,Zearalenone,etc.),and reproducibility(RSD=0.69%)and repeatability(RSD=0.59%),offering a robust,high-performance solution the detection of trace mycotoxins in complex food matrices.
基金
funded by the Key Scientific and Technological Project of Henan Province(242102320270)
Special Project for Collaborative Innovation of Zhengzhou(21ZZXTCX15)
Henan University of Technology Postdoctoral Scientific Research Fund(21450082).
