Decoration of Covalent Polyoxometalate-Organic Frameworks with Pt Nanoparticles and Multiwalled Carbon Nanotubes for Simultaneous Electrochemical Detection of Hydroquinone and Catechol

Abstract

Hydroquinone (HQ) and catechol (CC) are isomers with similar structures, which destroyed ecosystem balance and human health at an alarming rate. Therefore, it is critical to monitor HQ and CC in the environment simultaneously. Herein, a sensitive electrochemical sensor based on multiwalled carbon nanotubes and covalent polyoxometalate-organic frameworks (CPOFs) modified by nanoparticles (PtNPs@CPOFs-MWCNTs) was designed for the simultaneous detection of HQ and CC. Polyoxometalates (POMs) have been extensively studied in the area of electrochemical sensors because of rich reversible multielectron redox behavior. The porous and long stick-shaped CPOFs was synthesized by solvothermal Schiff base reaction, with NH 2 -POM-NH 2 and 2,5-dimethoxy-phenyl-1,4-diformaldehyde as monomers. Using the porosity and large surface area of CPOFs, the obtained PtNPs@CPOFs nanocomposite showed an improved distribution of electroactive sites. At the same time, highly conductive MWCNTs was incorporated to guarantee the conductivity.

Advances in polyoxometalate-based electrochemical sensors in the last three years

“…POM-based ECSs have been applied to detect contaminants in water and in the atmosphere ( e.g. heavy metal ions, 46,48,68,74 inorganic salt pollutants, 33,34,45,75,76 organic pollutants, 35,76–79 drugs 46,52 ), showing great promise in environmental monitoring.…”

“…2c). 79 These studies are supposed to provide valuable ideas for developing POM-based ECSs to detect organic contaminants in a water environment.…”