An Innovative Sb-W-Cotemplated Antimonotungstate with Potential in Sensing Paroxetine Electrochemically.

Advances in polyoxometalate (POM) self-assembly chemistry are always accompanied by new developments in molecular blocks. The exploration and discovery of uncommon building blocks offer great possibilities for generating unprecedented POM clusters. An intriguing Sb-W-cotemplated antimonotungstate [HN(CH)]Na[SbWO]Er(HO)Sb[SbWWO]·22HO () was synthesized, which comprises a classical trivacant Keggin [SbWO] ({SbW}) fragment and an unclassical lacunary Dawson-like [SbWWO] ({SbWW}) subunit. Notably, the Dawson-like {SbWW} subunit is the first example of a [SbO] and [WO] mixed-heteroatom-directing POM segment. Hexacoordinated [WO] can not only serve as the heteroatom function but its additional oxygen sites can also link to lanthanide, main-group metal, and transition-metal centers to form the innovative structure. {SbWW} and {SbW} subunits are joined by the heterometallic [Er(HO)SbO] cluster to give rise to an asymmetric sandwich-type architecture. To further realize its potential application in electrochemical sensing, a conductive @rGO composite was obtained by the electrochemical deposition of with graphene oxide (GO). Using a @rGO-modified glassy carbon electrode as the working electrode, an electrochemical biosensor for detecting the antidepressant drug paroxetine (PRX) was successfully constructed. This work can provide a viable strategy for synthesizing mixed-heteroatom-directing POMs and demonstrates the application of POM-based materials for the electrochemical detection of drug molecules.