A ratiometric electrochemical sensor based on Cu@Ni/MWCNTs for detection of chloramphenicol

Signal label features robust stability and sensitivity is crucial for achieving precise electrochemical analysis. In this work, a novel signal tag was successfully designed by means of two-step reduction approach, in which CuNi nanoparticles (CuNi NPs) uniformly distributed on the surface of multiwall carbon nanotubes (MWCNTs). This composites not only inherits excellent conductivity and surface area of MWCNTs, but also endows the material with superior electrocatalytic performance due to the introduction of CuNi NPs. Then, a ratiometric sensing platform coupled with built-in correction ability for convenient direct determination of chloramphenicol (CAP) was exploited, wherein Cu@Ni/MWCNTs were used as signal label and ferrocene (Fc) as internal reference. It is noteworthy that ratiometric measurement was performed by directly incorportating Fc into the electrolyte solution. The profound investigation into the sensing performance of the implemented sensor revealed that Cu@Ni/MWCNTs nanocomposites exhibit satisfactory electrocatalytic activity and stability. Additionally, the integration of the ratiometric strategy markedly enhanced the reliability and repeatability and exhibited decent performance in CAP determination varying from 0.01 µM to 10 µM. Overall, the corporation of Cu@Ni/MWCNTs with excellent electrocatalytic ability as well as elaborated ratiometric method makes it a valuable tool for future assaying an extensive range of substances.