An electrochemical sensor employing a molecularly imprinted-aptamer synergistic recognition strategy based on Cu-Zr bimetallic MOF-818 for the highly sensitive detection of zearalenone

This study developed an electrochemical sensor incorporating a dual recognition strategy that integrates molecularly imprinted polymer (MIP) and aptamers for the ultra-sensitive detection of zearalenone (ZEN) in grains. Exploiting the high specific surface area of the Cu-Zr bimetallic metal-organic framework-818 (MOF-818), aptamers were covalently immobilized on the olefin-functionalized MOF-818 surface via thioenol reaction. Employing 3-thiopheneacetic acid functionalized gold nanoparticles (3-TAA@AuNPs) as functional monomers, nanoscale molecularly imprinted cavities were electro-polymerized onto the modified electrode surface in the presence of the ZEN template. This synergistic recognition system integrates the aptamer's specific binding capability with the spatial complementarity of MIP, displaying an excellent linear response over a concentration range of 10 −13 to 10 −5  g/L and a detection limit as low as 2.8 × 10 −14  g/L. Analysis of real samples exhibited ZEN recoveries ranging from 96.5 % to 105.0 % (RSD <5.2 %) in corn and wheat matrices, confirming its practical applicability for rapid screening of fungal toxins in agricultural commodities.