Three-dimensional porous carbon/covalent-organic framework films integrated electrode for electrochemical sensors

Covalent organic frameworks (COF) thin films were formed on three-dimensional porous carbon (3D-KSC) for constructing highly sensitive enzyme-free electrochemical sensors. The layered COFTAPB-PDA was distributed on pore's wall of 3D-KSC, which improved effective specific surface area of 3D-KSC and functional sites. The spherical Cu nanoparticles (NPs) and PtNPs were deposited directly on the 3D-KSC/COFTAPB-PDA electrode by electrostatic potential deposition. The electrochemical behaviors, electrocatalytic glucose oxidation and electrocatalytic H2O2 reduction at 3D-KSC/COFTAPB-PDA/CuNPs and 3D-KSC/COFTAPB-PDA/PtNPs integrated electrode were explored by cyclic voltammetry, electrochemical impedance and chronoamperometric method. The results showed that the linear range of glucose detection by 3D-KSC/COFTAPB-PDA/CuNPs integrated electrode was 4.69 mu M - 1.57 mM and 1.57 mM-7.07 mM with the detection limit of 1.54 mu M. The linear range of the detection of H2O2 by 3D-KSC/COFTAPB-PDA/PtNPs integrated electrode was 18.5 nM-5.4 mu M and 5.4 mu M-3055.4 mu M with the detection limit of 6.0 nM. The selectivity, repeatability and stability of the two sensors were also studied. The results showed that they had high selectivity, good repeatability and good stability.