Synthesis of bimetallic covalent organic framework nanocomposite for enhanced electrochemical detection of gallic acid

Here, a novel core-shell structured FeNi/covalent organic framework (TAPB-DMTP-COF) nanocomposite was synthesized by the formation of covalent organic framework shell on the surface of FeNi alloy core. The struc-tural and electrochemical characteristics of the material were analyzed using powder X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray photoluminescence spectroscopy, and cyclic voltammetry. Due to the synergistic effects of high catalytivity of FeNi and large surface area of TAPB-DMTP-COF, FeNi@TAPB-DMTP-COF core-shell nanocomposite demonstrated excellent electrochemical oxida-tion response toward gallic acid. The parameters affecting the analytical procedure, such as buffer solution pH, scan rate, accumulation potential and time, were optimized. Under the optimal conditions, the electrochemical sensor exhibited two linear relationships with the wide gallic acid concentration in the range of 0.005-7.0 and 7.0-400 mu mol/L, and the detection limit was calculated to be 1.3 nmol/mL (S/N = 3). The feasibility of the established method was successfully assessed by analyzing the content of gallic acid in real samples, and good recoveries were achieved. Our work thus paves a way to exploit bimetallic COF with high conductivities and electrocatalytic performances in electrochemical biosensors.