Thiol-grafted covalent organic framework-based electrochemical platforms for sensitive detection of Hg(ii) ions

Triazine-based covalent organic frameworks functionalized by thiol and thioether (COF_S-CH3/COF_S-SH) were designed and served as a platform that could bind with mercury ions specifically based on Hard-Soft-Acid-Base theory. As such, when employing COFs as a modifier in a carbon paste electrode (CPE), the COF_S-CH3-modified CPE revealed an extraordinary performance (detection limit of 0.01 ppb; linear range of 0.1 to 1.0 ppb) and repeatability for electrochemical detection of trace mercury, even in real samples collected from tap or lake water. This innovative approach leverages the inherent properties of covalent organic frameworks (COFs) to enable highly sensitive and selective detection of target analytes.