A covalent organic frameworks@gold nanoparticles@graphene nanocomposite based electrochemical sensor for simultaneous determination of trace Cd2+, Pb2+ and Cu2+

It's very exciting to develop an electrochemical sensor for simple, rapid and simultaneous determination of heavy metal ions in Baijiu by applying new nanocomposites. Herein, a novel COFDPTB@gold nanoparticles (AuNPs)@graphene (GR) was obtained via combining COFDPTB synthesized using the Schiff-base condensation between 2, 5-dimethoxyterephthalaldehyde and 1, 3, 5-tris(4-aminophenyl) benzene with AuNPs and GR. Owing to the high porosity and abundant adsorption sites of COFDPTB, the outstanding electrical conductivity of AuNPs and GR, as well as the high specific area and synergy of COFDPTB, AuNPs and GR, the proposed sensor exhibited excellent analysis performance for the detection of Cd2+, Pb2+ and Cu2+. Under optimized conditions, the sensor showed good linearity range of 0.5–18 μM for Cd2+, and both 0.5–6.0 μM for Pb2+ and Cu2+ with the detection limits of 3.025 nM, 5.849 nM and 9.993 nM, respectively. In addition, the recovery measurement suggested the practicality of the prepared sensor.