Engineering high-affinity and selective molecular recognition redox active imprinted platform on carbon cloth for...

A novel dual-functional redox-controllable molecularly imprinted polymer (MIP)-based electrochemical sensor for the sensitive detection and efficient microextraction of aflatoxin B1 (AFB₁) was developed in this study, filling an essential void in food safety monitoring. The β-CFe@MIP/CC sensor was engineered by UV-curing beta-cyclodextrin-ferrocene (β-CFe) conjugates and conventional monomers onto a carbon cloth matrix. The synergistic role of β-cyclodextrin (βCD) to increase host-guest interaction ensures high selectivity towards AFB₁, and ferrocene (Fe) enhances redox cycling efficiency, enhancing the electrochemical signal. Specifically, the binding of AFB₁ with β-CFe@MIP/CC through recognition pockets that controlled the electron transfer and exhibited an imprinting factor (IF) ∼ 6 thus accurately detecting the toxins. The sensor showed an excellent linear detection range of 0.3-1500 ng/mL, LOD of 0.03 ng/mL and LOQ of 0.1 ng/mL. The sensor exhibited excellent reproducibility across real milk, wheat and corn samples with a recovery rates between 98.6 and 104.7 % with low RSD values (0.35-2.83 %) and displayed remarkable selectivity, differentiating AFB₁ from structurally related mycotoxins. This bimodal sensor exhibited extraordinary microextraction efficiency for AFB₁ in milk samples, extensively reducing the contamination levels across all tested concentrations. The obtained results were validated with standard High-performance liquid chromatography (HPLC) analysis of the milk samples pre and post-incubation with β-CFe@MIP/CC. The sensor's high adsorption capacity, binding specificity and detoxification efficacy establish it as a superior tool for integration into routine milk quality monitoring systems.