Interfacial regulation of cobalt-nickel/nitrogen-doped carbon nanospheres and its electrochemical sensing performance for detection of chloramphenicol

Chloramphenicol （CAP）， as an antibiotic， is widely used as a veterinary medicine in the aquaculture industry. The misuse of CAP can lead to a range of environmental and human health issues， making it extremely important to establish a rapid and sensitive method for detecting CAP. Electrochemical sensors have been widely studied by researchers due to their advantages of simple operation， rapid response， high sensitivity， and ease of miniaturization， but their performance mainly depends on the sensing material. In this work， cobalt-nickel metal-organic framework （CoNi-MOF） is in situ synthesized on the surface of bacteria. CoNi nitrogen-doped carbon nanospheres （CoNi/CN-900） with abundant active sites and a large specific surface area is obtained after carbonization at 900 ℃ by interfacial regulation. The uniform distribution of Ni and Co on CoNi/CN-900 provides more catalytically active sites for the detection of CAP. The CoNi/CN-900-based CAP electrochemical sensor shows a good linear range of 20 nmol/L- 4 μmol/L and 4-38 μmol/L， a detection limit as low as 6.6 nmol/L， and a high sensitivity of 8.75 μA·μmol·L-1·cm-2. Compared with the reported same type sensors， it has higher sensitivity and a lower detection limit. In addition， the sensor has good selectivity and high stability， which can keep more than 99.1% of its initial current at room temperature for 35 days.