A Lanthanide-Incorporated Phospho(III)tungstate Aggregate Constructed from [HP III W 8 O 31 ] 10- and [W 11 O 39 ] 12- Building Blocks and Its Nanocomposite with CdS for Ultrasensitive Photoelectrochemical Detection of Oxytetracycline.

A novel tartronic acid decorated hexa-Ce III -incorporated phospho(III)tungstate aggregate (C 4 H 12 NO) 6 Na 18 H 2 [(HPW 8 O 31 ) 2 [W 11 O 39 ] 2 (H 2 TAD) 4 (H 2 O) 4 W 4 Ce 6 H 2 P 2 O 14 ]·84H 2 O ( 1 , H 3 TAD = tartronic acid) was synthesized by a one-step assembly strategy. Its main skeleton is constructed from two [W 11 O 39 ] 12- fragments, two [HP III W 8 O 31 ] 10- segments and one H 2 TAD - -ornamented dodecanuclear heterometallic [W 4 Ce 6 H 2 P III 2 O 14 (H 2 TAD) 4 (H 2 O) 4 ] 18+ cluster. In the structure, the [HP III O 3 ] 2- groups not only work as the heteroatom template to induce the formation of lacunary [HP III W 8 O 31 ] 10- segments but also function as the connector to bridge Ce 3+ cations. With the help of a reaction strategy of combining ultrasonication treatment with the continuous ion layer adsorption method, the 1 /CdS composite was constructed and exhibits prominent photoelectrochemical activity. The 1 /CdS composite was used as a photoelectrochemical sensor for oxytetracycline detection at 0 V (vs Ag/AgCl), which displays excellent properties with quick response and low limit of detection (0.042 nM). This work can provide some helpful references in the construction of novel P III -induced polyoxometalates consisting of different building blocks and can extend the applications of polyoxometalate-based nanocomposites into photoelectrochemical detection for antibiotics as well as biomolecules.