An Innovative Sb III -W VI -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 ^III -W ^VI -cotemplated antimonotungstate [H ₂ N(CH ₃ ) ₂ ] ₁₁ Na[SbW ₉ O ₃₃ ]Er ₂ (H ₂ O) ₂ Sb ₂ [SbW ^VI W ₁₅ O ₅₇ ]·22H ₂ O ( 1 ) was synthesized, which comprises a classical trivacant Keggin [SbW ₉ O ₃₃ ] ^9- ({SbW ₉ }) fragment and an unclassical lacunary Dawson-like [SbW ^VI W ₁₅ O ₅₇ ] ^15- ({SbW ^VI W ₁₅ }) subunit. Notably, the Dawson-like {SbW ^VI W ₁₅ } subunit is the first example of a [SbO ₃ ] ^3- and [W ^VI O ₆ ] ^6- mixed-heteroatom-directing POM segment. Hexacoordinated [W ^VI O ₆ ] ^6- 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. {SbW ^VI W ₁₅ } and {SbW ₉ } subunits are joined by the heterometallic [Er ₂ (H ₂ O) ₂ Sb ₂ O ₁₇ ] ^22- cluster to give rise to an asymmetric sandwich-type architecture. To further realize its potential application in electrochemical sensing, a conductive 1 @rGO composite was obtained by the electrochemical deposition of 1 with graphene oxide (GO). Using a 1 @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.