An electrochemical aptasensor based on C-ZIF-67@PAN nanofibers for detection of ampicillin in milk.

C-ZIF-67@PAN nanofibers are prepared as an active material for ampicillin (AMP) detection. Metal organic frameworks (MOFs) can provide larger specific surface area and more binding sites. The PAN fiber in the further carbonization process can make ZIF-67 orderly arranged, enhance the conductivity of the material, and make the response more sensitive. Gold nanoparticles are incorporated into the material, and the aptamer is closely combined with the material by using the Au-S bond to further enhance the conductivity of the material. Under optimized conditions, the sensor has a wide detection range (0.001-100 μM) and a low detection limit (0.67 nM). In addition, the C-ZIF-67@PAN@Au@Apta sensor is successfully applied to AMP residues in milk samples with a recovery rate of 92.77-101.95%.