Double Trigonal Pyramidal {SeO 3 } Groups Bridged 2-Picolinic Acid Modified Cerium-Inlaid Polyoxometalate Including Mixed Selenotungstate Subunits for Electrochemically Sensing Ochratoxin A.

An organic-inorganic hybrid trigonal pyramidal {SeO 3 } group, bridged cerium-inlaid polyoxometalate (POM) Na 16 [Se 2 Ce 4 (H 2 O) 8 W 4 (HPIC) 4 O 10 ][B-β-SeW 8 O 30 ] 2 [Se 2 W 12 O 46 ] 2 ·60H 2 O ( 1 ) (HPIC = 2-picolinic acid), containing two disparate selenotungstate (ST) building blocks was synthesized by a one-step assembly strategy, which is established by two asymmetric sandwich-type {[Ce 2 (H 2 O) 4 W 2 (HPIC) 2 O 4 ][B-β-SeW 8 O 30 ][Se 2 W 12 O 46 ]} 10- moieties joined by double trigonal pyramidal {SeO 3 } groups. Its outstanding structural trait is that it contains two types of ST building blocks, Keggin-type [B-β-SeW 8 O 30 ] 8- and Dawson-like [Se 2 W 12 O 46 ] 12- , which are extremely rare in ST chemistry. Remarkably, [Se 2 W 12 O 46 ] 12- is first obtained in lanthanide-inlaid STs. Furthermore, 1 @PPy conductive film (PPy = polypyrrole) was prepared by electrochemical polymerization and served as the electrode material, and then nano-gold particles (NGPs) were deposited on the surface of 1 @PPy conductive film by an electrochemical deposition method in order to immobilize the aptamer of ochratoxin A. With the help of exonuclease I (EN I), the oxidation peak of the metalized Ag works as the detection signal to achieve the detection of ochratoxin A (OTXA). This study offers an available approach for creating organic-inorganic hybrid heteroatom-bridged lanthanide-inlaid POMs and reveals the likelihood of extending heteroatom-bridged lanthanide-inlaid POMs into electrochemical biosensing applications.