Electrochemical and colorimetric dual-channel biosensor based on B and N co-doped carbon nanotubes

Rational design of efficient metal-free doped carbon nanotubes to construct dual-channel sensing platforms remains a challenge. In this study, B and N co-doped carbon nanotubes (BNCNTs) were designed and produced by one-step pyrolysis of P123, boric acid and urea, in which P123 could act as a structural guide to promote the generation of nanotubes. The synergistic effect of B and N doping can modulate the electronic structure of the skeleton, where B can reduce the valence band and the N could excite the conduction band. This can promote electron transport and create more active sites. As a result of the hollow tubes and the synergistic effect of B and N doping, the BNCNTs are an excellent electrocatalyst which could be candidates for electrode modification materials. In addition, the BNCNTs also exhibit excellent peroxidase activity. Therefore, BNCNTs were employed conduct an electrochemical and colorimetric dual channel sensing platform for the detection of uric acid in the range of 2–400 μM and 5–200 μM, with the detection limits of 0.078 μM and 4.52 μM, respectively. This work presents a method for the preparation of metal-free doped carbon nanotubes as multifunctional catalysts for applications in nanozymes, sensing, clinical diagnostics, and other fields.