Exploration of cobalt-based colorimetric aptasensing of zearalenone in cereal products: Enhanced performance of Au/CoOOH nanozyme

Zearalenone (ZEN) poses significant threats to food safety and human health due to its widespread contamination in cereals. Current detection methods face limitations in cost, complexity, and field applicability. To address this, we developed a novel colorimetric aptasensor leveraging the peroxidase-like activity of Au/CoOOH nanozymes for rapid and sensitive ZEN detection. Systematic characterization of cobalt-based nanomaterials (β-Co(OH) 2 , Co 3 O 4 , CoOOH, and Au/CoOOH) revealed that Au/CoOOH exhibited the highest catalytic efficiency, achieving a 3.5-fold enhancement over CoOOH due to synergistic interactions with Au nanoparticles. The aptasensor employed a competitive displacement strategy: ZEN binding to aptamer-functionalized magnetic beads released cDNA-conjugated Au/CoOOH, reducing 3,3′,5,5′-tetramethylbenzidine oxidation signals. Optimized parameters enabled a linear detection range of 0.3–500 ng/mL with a detection limit of 0.23 ng/mL. Specificity tests confirmed minimal cross-reactivity with other mycotoxins. The sensor demonstrated exceptional sensitivity, specificity, and practicality, validated by recovery rates of 90.65–105.63 % in spiked matrices, positioning it as a reliable tool for safeguarding food safety through rapid, precise mycotoxin monitoring.