Two New Preyssler-Type Polyoxometalate-Based Coordination Polymers and Their Application in Horseradish Peroxidase Immobilization

Graphical Pinning down catalysts : Two new Preyssler-type polyoxometalate-based coordination polymers were synthesized and applied to immobilize horseradish peroxidase (HRP). These polymers exhibited higher enzyme loading, required a shorter loading time, and exhibited excellent reusability (see figure). Enzyme immobilization is of increasing importance for biocatalysis, for which good supports are critical. Herein, two new Preyssler-type polyoxometalate (POM)-based coordination polymers, namely, {[Cu(H 2 biim) 2 ][{Cu(H 2 biim) 2 (μ-H 2 O)} 2 Cu(H 2 biim)(H 2 O) 2 ]H[({Cu(H 2 biim)(H 2 O) 2 } 0.5 ) 2 ((μ-C 3 HN 2 Cl 2 ){Cu(H 2 biim)} 2 ){Z(H 2 O)P 5 W 30 O 110 }] ⋅ x H 2 O} n ( 1 : Z=Na, x= 9; 2 : Z=Ag, x= 10; H 2 biim=2,2′-biimidazole) were designed and synthesized. Compounds 1 and 2 exhibit the same skeletons, which contain multiple Cu II complex fragments and penta-supported {ZP 5 W 30 } (Z=Na, Ag) clusters. They were first employed to immobilize horseradish peroxidase (HRP). Results show that compounds 1 and 2 are good supports for HRP immobilization, and exhibit higher enzyme loading, lower loading times, and excellent reusability. The immobilized HRP (HRP/ 1 or HRP/ 2 ) was further applied to detect H 2 O 2 , and good sensitivity, wide linear range, low detection limit, and fast response were achieved. This work shows that POM-based hybrid materials are a new kind of promising support for enzyme immobilization.