Immunosensor Based on Screen-Printed Graphite Electrodes Modified with Gold Nanoparticles and a Synthetic Membrane-Like Substance for the Determination of Chloramphenicol

An electrochemical immunosensor based on screen-printed graphite electrodes is developed for the determination of the antibiotic chloramphenicol in water and milk samples. It is shown that the immobilization of chloramphenicol-specific antibodies in the liquid-crystal layer of the membrane-like didodecyldimethylammonium bromide preserves the mobility and accessibility of active centers of antibodies, and the addition of gold nanoparticles improves the electron transfer from the electrode surface to the redox centers of horseradish peroxidase, which is used as a label. The limit of detection of chloramphenicol is 0.02 μg/L in water and 0.04 μg/L in milk. This method can be used to determine the residual amounts of chloramphenicol in animal products.