Molecularly imprinted electrochemical sensor for ultrasensitive determination of chloramphenicol in milk and egg...

Chloramphenicol (CAP) is an antibiotic that could cause serious toxic effects on the human body. Therefore, it is crucial to measure CAP levels in food products. Here we developed an electrochemical sensor based on the molecularly imprinted polymer/polyaniline/gold nanoparticles-reduced graphene oxide-chitosan (MIP/PAN/AuNPs-RGO-CS) modified electrode to determine CAP. The PAN/AuNPs-RGO-CS and MIP film provided the function of signal amplification element and specific recognition unit, respectively. CAP was detected by square-wave voltammetry using potassium ferricyanide (K₃Fe(CN)₆) as a redox signaling probe. The reduction peak current of K₃Fe(CN)₆ linearly decreased with the logarithmic CAP concentration in two distinct ranges of 1.0-8.0 nM and 10-200 nM with a low limit of detection of 63 pM. This sensor also exhibited short removal and adsorption time, good repeatability, high selectivity, excellent stability, and acceptable recoveries for milk and egg, which offered a promising avenue for ultrasensitively measuring trace antibiotics in actual samples.