Biochar-supported Cu nanocluster as an electrochemical ultrasensitive interface for ractopamine sensing

Electrochemical sensors actually involve an electrocatalytic process involving an efficient and selective energy conversion that is related to the morphology and size of the interface of the modified materials. Ultrasmall nanoclusters or single atoms generate a greater catalytic ability than normal nanomaterials. In this study biochar-supported Cu nanoclusters (CuNCs@CNFs) were fabricated via a carbon confinement synthesis method toward ultrasensitive electrochemical sensing of ractopamine (RAC). RAC is a β-adrenergic receptor agonist that is illegally used as a feed additive to significantly improve muscle accretion, resulting in RAC accumulation in meat-based food products. The unique structure of CuNCs@CNFs and the interconnectivity between the CuNCs and the CNFs enable the nanocomposite to significantly enhance conductivity and electrocatalytic activity. Using the CuNCs@CNFs-based sensor, RAC was determined with a high sensitivity of 1641 μA μM^-1 cm^-2. The feasibility of detecting RAC in spiked meat samples was also carried out with satisfactory recoveries ranging from 91.39 % to 94.58 %.