Novel dual-recognition electrochemical biosensor for the sensitive detection of AFM₁ in milk

Aflatoxin M₁ (AFM₁) is a highly carcinogenic and toxic compound that is commonly found in dairy foods such as milk. We developed an electrochemical MIP (molecularly imprinted polymer) and aptamer (Apt) based aptasensor (Apt-Au@PEIM/AFM₁/MIP-Apt/AuNPs)/GCE) with dual-recognition signal amplification to detect AFM₁ in milk. The MIP-Apt/AuNP/GCE sensor was prepared by synthesizing an MIP film through the electropolymerization of resorcinol on gold nanoparticles-modified electrodes. The dropwise addition of our cApt-Au@PEIM signal amplification probe could enhance the current signal response and improve the sensitivity of the sensor to detect AFM₁. The AFM₁ present in milk could prevent the probe from binding to the sensor, thereby drastically reducing the current signal. Under optimal experimental conditions, the sensor exhibits a linear range of 0.01-200 nM and a limit of detection of 0.07 nM (S/N = 3). The developed dual-recognition aptasensor would provide a novel and rapid method for specific detection of AFM₁ in milk.