LAUSR

Under coordination driving force of tungsten and rare-earth (RE) bridges, we synthesized a novel giant multi-tungsten-and-RE-bridging octameric tellurotungstate (TT) [H2N(CH3)2]16K8Na6H10[Pr8(H2O)20W16O48][B-α-TeW9O33]8·70H2O (1) in CH3CN-H2O mixed solvent. The cluster anion {[Pr8(H2O)20W16O48][B-α-TeW9O33]8}40- features sixteen WVI bridges, eight PrIII bridges and eight trivacant Keggin [B-α-TeW9O33]8- fragments, which the square {W4O12} cluster can be imagined as a seed to induce the aggregation of eight [B-α-TeW9O33]8- fragments by coordination driving force of additional twelve WVI bridges and eight PrIII ions. Furthermore, the 2D 1@DODA (dimethyldioctadecyl ammonium bromide = DODA·Br) honeycomb composite material was prepared. The honeycomb morphology of the 1@DODA composite material provides rich binding sites for electrodepositing Au nanoparticles to make Au/1@DODA electrodes. The aptamer of 17β-estradiol (E2) hormone can be grafted to the Au/1@DODA electrodes via Au-S bonding interaction to construct the Au/1@DODA aptamer biosensors. By virtue of the specific recognition interaction of aptamer and the electrochemical signal amplification function of methylene blue and cDNA, the Au/1@DODA aptamer biosensors can realize the electrochemical detection of E2. This finding not only offers an electrochemical biosensing platform for detecting E2, but also expands POM-based composite materials in the applications of clinical detection and biological analysis.