Two Types of Subgroup-Valence Heteroatoms (P<sup>III</sup>, Te<sup>IV</sup>) Synergistically Controlling Octa-Ce<sup>III</sup>-Encapsulated Heteropolyoxotungstate and Its Electrochemical Recognition Properties
Juan Li, Nizi Song, Menglu Wang, Zhimin Zhang, Yanzhou Li, Lijuan Chen, Junwei Zhao
Abstract
Rapid development of the synthetic chemistry of polyoxometalates (POMs) has greatly driven the generation of structurally variable innovative POM-based materials. Herein, we synthesized a novel PIII and TeIV synergistically controlling octa-CeIII-encapsulated heteropolyoxotungstate [H2N(CH3)2]11K2Na6H11[Ce8(CH3COO)2(HPIIIO3)2W8O20(H2O)12(B-β-TeW8O30)2(B-α-TeW8O31)4]·64H2O (1). Its distinctive anion skeleton [Ce8(CH3COO)2(HPIIIO3)2W8O20(H2O)12(B-β-TeW8O30)2(B-α-TeW8O31)4]30– is built by two tetra-vacancy [B-β-TeW8O30]8– and four tetra-vacancy [B-α-TeW8O31]10– moieties linked through an inorganic–organic hybrid [Ce8(CH3COO)2(HPIIIO3)2W8O20(H2O)12]26+ {Ce8P2W8} cluster core. Interestingly, {Ce8P2W8} is assembled from four [W2O11]10– groups and two [HPIIIO3]2– anions and eight Ce3+ ions. Besides, 1 was further composited with carboxylated multiwalled carbon nanotube (CMCN), resulting in a bi-component 1/CMCN nanocomposite. An electrochemical recognition platform (named as 1/CMCN/GCE) was built by modifying 1/CMCN on a glassy carbon electrode (GCE) for electrochemical detection of dopamine (DPA) at physiological pH (pH = 7.0). The findings have shown that 1/CMCN/GCE exhibits a good detection limit of 4.95 nM for DPA. This work provides considerable inspiration to promote innovative and rational structure designs of POM-based materials and expand their applications to electrochemical and biological detection fields.