Carbon black imprinted o-diaminobenzene sensing platform for sensitive electrochemical detection of interleukin 6

As a typical proinflammatory cytokine, interleukin 6 (IL-6) exhibits great influence on treating diseases (e.g., urocystitis) and adjusting immune. Normally, the IL-6 degree keeps a low content (< 40.0 pg mL^-1) in bodies, but when its degree becomes higher, several serious conditions (e.g., urocystitis and infections) may occur. Hence, it is very essential to design a highly effective technology for monitoring IL-6 as a biomarker. In the present work, through adopting carbon black (CB) as substrate substance, o-diaminobenzene as electropolymerized monomer and [Fe(CN)₆]^4-/3- as the signal probe, a low-cost, sensitive and simple molecularly imprinted polymer (MIP) electrochemical sensing platform was designed to detect the IL-6 degree. The experiments revealed that the current of [Fe(CN)₆]^4-/3- probe at the MIP sensor would decrease along with the increase of IL-6 degree. Owing to the prominent properties of CB (e.g., high conductivity and surface area as well as stability) and high target-recognition capability of MIP, the as-proposed MIP sensor offers wide linearity (0.1-800 pg mL^-1) and low analytical limit (0.03 pg mL^-1); meanwhile, it possesses good repeatability, stability, and practical applications. It is, thus, expected this simple MIP sensor has some application value for IL-6 detection.