A Effectively Sensing Composite Derived From AgNPs and Cu (II)‐PMo ₁₂ ‐Based Complex: Electrochemical Detection for Hg ²⁺ and Epicatechin

The detection of mercury ion in soil and active biomolecule in food is of great significance. In this study, a new polyoxometalate‐based supramolecular framework derived from electrochemical active PMo 12 O 40 3− and Cu‐pp subunits {[Cu (pp) 2 ] [Cu (pp) 2 ](PMo 12 O 40 )(HPMo 12 O 40 )][Cu (pp) 2 (CH 3 O)]}·(CH 3 OH)(H 2 O) 2 ( 1 ) [pyridine pyrazole (pp)] was obtained by CH 3 OH‐H 2 O mixed solvothermal. Utilizing the reducing action of NaBH 4 , silver nanoparticles (AgNPs) were modified on the surface of the title compound 1 to generate an effective electrochemical sensing composite material (AgNPs@ 1 ). Single crystal X‐ray diffraction, elemental analysis (EA), infrared (IR) spectroscopy, X‐ray powder diffraction (PXRD), electrochemical impedance spectroscopy (EIS), and X‐ray photoelectron spectroscopy (XPS) were used for the corresponding characterization of the above materials. AgNPs@ 1 ‐modified carbon paste electrode (AgNPs@ 1 ‐CPE) was fabricated and used for the detection of Hg 2+ and epicatechin (EC) in H 2 SO 4 /Na 2 SO 4 electrolyte system with robust anti‐interference capabilities, stability, and low detection limit (20 nM for Hg 2+ and 84 nM for EC). The practical application of the corresponding detection was explored for the river mud and tea drinks.