A portable screen-printing electrode modified by COFDATA-TP with abundant carboxyl and secondary amine groups for simultaneous detection of Hg2+, Cu2+, Pb2+, and Cd2+

Based on the idea of constructing a miniature electrochemical sensor, a covalent-organic framework (COFDATA-TP) material was designed and synthesized to modify screen-printing electrode (SPE) to simultaneously detect heavy metal ions (Hg2+, Cu2+, Pb2+, and Cd2+). The COFDATA-TP was prepared by amine-aldehydes condensation of 2,5-diamino-1,4-phenyldicarboxylic acid (DATA) and 2,4,6-triformylphloroglucinol (TP). The COFDATA-TP contains lots of uniformly distributed -COOH and NH on pore's wall, which can be used as heavy metal ion adsorption sites. It was used to detect trace heavy metal ions in water sensitively when it was modified on a large-scale production disposable SPE. Moreover, the electrochemical sensor showed admirable detection limit and sensitivity when detecting four metal ions simultaneously. The sensitivities of COFDATA-TP/SPE to detect Hg2+, Cu2+, Pb2+, and Cd2+ are 7.65, 4.27, 11.68, and 7.34 mu A mu M-1, respectively. The detection limits of COFDATA-TP/SPE to detect Hg2+, Cu2+, Pb2+, and Cd2+ are 2.80, 5.01, 1.83, and 2.91 nM, respectively.

Automated summary

A COFDATA-TP material was synthesized and used to modify a screen-printing electrode (SPE) for simultaneous detection of heavy metal ions. The COFDATA-TP showed high adsorption capacity and sensitivity, making it suitable for rapid detection on a large-scale disposable SPE.