Recent research progress in polyoxometalate-based composite materials applied to electrochemical biosensors for biomolecule detection

Polyoxometalates (POMs), as a class of well-known metal-oxygen cluster materials, have exhibited exceptional multi-electron redox activity, reversible electron transfer capabilities and structural tunability, which render them promising candidates as electrode modification materials for electrochemical biosensors (ECBSs). To further enhance their performances, POMs are often combined with conductive materials to form POM-based composite materials (POMCMs). These POMCMs synergistically improve electron transport efficiency, stabilize biological recognition elements and amplify electrochemical signals, thereby significantly enhancing the sensitivity and selectivity of ECBSs. Consequently, POMCM-integrated ECBSs have enabled the sensitive detection of a wide range of biomolecules. This review summarizes the preparation methods of POMCMs as modified electrodes, elucidates the working principles of POMCM-integrated ECBSs and highlights major recent advances in biomolecule detection since 2020. Finally, current challenges facing POMCM-integrated ECBSs are discussed, along with potential strategies for addressing these issues, with the ultimate aim of facilitating the development of next-generation high-performance ECBSs.