Label-free immunoassay for chloramphenicol based on hollow gold nanospheres/chitosan composite

A novel label-free electrochemical immunosensor for rapid determination of chloramphenicol (CAP) was fabricated by entrapping monoclonal antibody to chloramphenicol (anti-CAP) in hollow gold nanospheres (HGNs)/chitosan composite modified on a glassy carbon electrode. The hollow gold nanospheres (HGNs) were prepared by using Co nanoparticles as sacrificial templates and characterized by transmission electron microscopy (TEM). The changes of the electrode behavior after each fabrication step were investigated by electrochemical impedance spectroscopy (EIS) technique. Under optimal conditions, the proposed immunosensor has a sensitive response to CAP in a linear range of 0.1-1000 ng mL−1 with the detection limit of 0.06 ng mL−1. Accurate detection of CAP in real meat samples was demonstrated by comparison with conventional HPLC method. The proposed method was proven to be a feasible quantitative method for CAP analysis with the properties of simple preparation, stability, high sensitivity and selectivity.