Enhancing the chloramphenicol sensing performance of Cu-MoS nanocomposite-based electrochemical nanosensors: roles of phase composition and copper loading amount.

The rational design of nanomaterials for electrochemical nanosensors from the perspective of structure-property-performance relationships is a key factor in improving the analytical performance toward residual antibiotics in food. We have investigated the effects of the crystalline phase and copper loading amount on the detection performance of Cu-MoS nanocomposite-based electrochemical sensors for the antibiotic chloramphenicol (CAP). The phase composition and copper loading amount on the MoS nanosheets can be controlled using a facile electrochemical method. Cu and CuO nanoparticle-based electrochemical sensors showed a higher CAP electrochemical sensing performance as compared to CuO nanoparticles due to their higher electrocatalytic activity and conductivity. Moreover, the design of Cu-MoS nanocomposites with appropriate copper loading amounts could significantly improve their electrochemical responses for CAP. Under optimized conditions, Cu-MoS nanocomposite-based electrochemical nanosensor showed a remarkable sensing performance for CAP with an electrochemical sensitivity of 1.74 μA μM cm and a detection limit of 0.19 μM in the detection range from 0.5-50 μM. These findings provide deeper insight into the effects of nanoelectrode designs on the analytical performance of electrochemical nanosensors.