A novel AuNPs-doped COFs composite as electrochemical probe for chlorogenic acid detection with enhanced sensitivity and stability

In this work, novel gold nanoparticles-doped TAPB-DMTP-COFs (TAPB, 1,3,5-tris(4-aminophenyl)benzene; DMTP, 2,5-dimethoxyterephaldehyde; COFs, covalent organic frameworks) composite was successfully prepared via COFs as the host matrix to support the growth of gold nanoparticles. With the strong electrostatic interaction between gold nanoparticles and unsaturated amine group present on TAPB-DMTP-COFs, the gold nanoparticles were successfully immobilized onto the surface of TAPB-DMTP-COFs under vigorously stirring. Then, this novel composite was used to constitute an advanced electrochemical sensor and presented a good electrocatalytic activity toward the oxidation of chlorogenic acid (CGA) in the phosphate buffer solution (pH 7.0). After a series of experiments, this electrochemical sensor displays a wide linear range of 1.0 × 10−8 – 4.0 × 10−5 mol L−1, low detection limit of 9.5 × 10−9 mol L−1 as well as a good repeatability of 4.1% in 2.0 × 10−5 mol L−1 CGA after ten scanning rounds. Moreover, the sensor exhibits an excellent stability and maintains its catalytic activity at least 100 cycles. Our work not only provides a simple way to detect CGA quantitatively in real samples, but paves a new platform for COFs-based composite in biosensor.