Electrochemical response of a COF/MWCNT sensor based on a bifunctional COF towards dopamine and uric acid†

This study has successfully fabricated a novel electrochemical sensor utilizing a bifunctional covalent organic framework (COF) and multi-walled carbon nanotubes (MWCNTs) as core building blocks, aiming to achieve highly sensitive and selective detection of dopamine (DA) and uric acid (UA). Specifically, the bifunctional COF synthesized through an imine-based reaction has exhibited a substantial specific surface area. This characteristic has provided abundant binding sites for the post-modification of MWCNTs, and the synergistic interaction between the two components has endowed the sensor with exceptional analytical performance. This synergy has significantly enhanced the adsorption and enrichment capabilities of the modified electrode toward DA and UA. The constructed electrochemical sensor has demonstrated low detection limits (LODs) of 0.0316 μM for DA and 0.0581 μM for UA, along with broad linear ranges of 0.3–500 μM and 0.1–500 μM, respectively. Additionally, the sensor has displayed outstanding selectivity, repeatability, anti-interference ability, and long-term stability, highlighting its potential for applications in the field of electrochemical biosensing.