Functionalized polyoxometalate microspheres ensure selective adsorption of phosphoproteins and glycoproteins

Lacunary polyoxometalate (POM), [PW9O34](9-), grafts with a boronic acid group attached via an organosilane bridge assemble into microspheres, PW9-Si-APBA. The oxygen-rich and hydrophilic surface of POM facilitates the binding of phosphate groups in phosphoproteins and glycans in glycoproteins. While the metal-oxo in POM provides pi-pi interactions with the phosphate groups of phosphoproteins, the boronic acid group specifically binds to glycoproteins via the cis-diols of glycans. Therefore, these multi-driving forces ensure the selective adsorption of phosphoproteins and glycoproteins by PW9-Si-APBA microspheres in biological sample matrixes, even in the presence of very high protein abundance, i.e., BSA, at mass ratio of beta-ca/IgG/OVA/BSA = 1 : 1 : 1 : 200.

Automated summary

The unique structure of POM microspheres PW9-Si-APBA allows for selective adsorption of phosphoproteins and glycoproteins in biological samples, showing promising potential for practical applications.