3-D Antimonotungstate Framework Based on 2,6-H2pdca-connecting Iron-Cerium Heterometallic Krebs-type Polyoxotungstates for Detecting Small Biomolecules.

Abstract

An inorganic-organic hybrid 3-D FeIII-CeIII heterometallic antimonotungstate framework [Ce(H2O)5(2,6-pdca)]4H2[Fe4(H2O)6(SbW9O33)2]·38H2O (1) (2,6-H2pdca = 2,6-pyridine-dicarboxylic acid) has been synthesized via a hydrothermal method by the one-pot reaction of 2,6-H2pdca, FeCl3·6H2O, Ce(NO3)3·6H2O, and Na9[B-α-SbW9O33]·19.5H2O. Notably, the structural unit of 1 possesses a Krebs-type [Fe4(H2O)6(2,6-pdca)2(SbW9O33)2]10- subunit supported with four bridging [Ce(H2O)5(2,6-pdca)]+ moieties. It is worth highlighting that adjacent structural units are concatenated together through heterobimetallic bridges to construct a 3-D framework. Furthermore, cuboid nanocrystal 1' was prepared under mild hydrothermal conditions based on the electrostatic interaction between 1 and K+. The effects of concentration and time on the morphology of nanocrystal 1' were also studied. The cuboid nanocrystal 1' was used as a modified electrode material for simultaneous electrochemical detection of dopamine and acetaminophen. The 1'-modified glassy carbon electrode shows good selectivity and sensitivity for detecting dopamine and acetaminophen.