Cobalt nanoparticles decorated bamboo-like N-doped carbon nanotube as nanozyme sensor for efficient biosensing

• Bamboo-like N doped carbon nanotubes encapsulated with cobalt nanoparticles (Co-BNCNTs) was designed by one-step pyrolysis. • The bamboo-like structure could prevent the self-aggregation of the CoNPs, improve the stability of the CoNPs, and enhance the catalytic activity of the CoNPs. • The hollow tubular structure could shorten the distance for the reactants to reach the electrode surface and accelerate the mass transfer process. In this work, Co nanoparticles decorated bamboo-like N-doped carbon nanotubes (Co-BNCNTs) were design, which exhibited excellent oxidase-mimicking activity and could be served as a novel signal amplification platform for dopamine (DA) sensing. Co nanoparticles (CoNPs) encapsulated in bamboo-like N-doped carbon nanotubes (BNCNTs) could prevent their self-aggregation and expose more active sites. Besides, the N-doping in carbon materials could adjust the charge density and increase active sites. Moreover, the synergistic effect between CoNPs and BNCNTs also could contribute to enhance catalytic activity. In a word, excellent electrical conductivity, large electrochemically active area, multiple catalytically active sites are beneficial for DA detection. The Co-BNCNTs/GCE biosensor showed good stability and selectivity, a wide detection range of 0.5-150 μM, and a lower detection limit of 0.0342 μM. The Co-BNCNTs sensor was employed to detect the DA in the actual sample, which displayed a potential application in clinical diagnosis. Furthermore, our study presented an effective way to the synthesis of metal nanoparticles encapsulated into CNTs catalysts as nanozymes for the application in biosensing.