A Heterometallic Decanuclear Ce III –W VI Cluster Incorporated Antimonotungstate for Sensitive Electrochemical Detection of Multidrug Resistance Genes

Multidrug resistance genes (MDRG) overexpression represents a critical factor contributing to chemotherapeutic resistance in cancer, necessitating the development of highly sensitive detection technologies for early diagnosis. Herein, we synthesized a heterometallic decanuclear CeIII-WVI cluster incorporated antimonotungstate pentamer Na₁₆H₇[Ce₄W₆O₁₃(H₂O)₁₂][B-α-SbW₉O₃₃]₅·40H₂O (1) via the reaction of the [B-α-SbW₉O₃₃]⁹⁻ precursor with Ce³⁺ cations in CH₃COOH-CH₃COONa buffer system. Its polyanionic architecture comprises a heterometallic decanuclear [Ce₄W₆O₁₃(H₂O)₆]²²⁺ core encapsulated by five [B-α-SbW₉O₃₃]⁹⁻ units. Notably, 1 represents the first reported pentamer within the rare-earth incorporated antimonotungstate family. By employing 1 as a multifunctional dopant, an electroconductive 1@PNMPy film was fabricated through electropolymerization of N-methylpyrrole (NMPy), demonstrating enhanced conductivity and stability. The resulting 1@PNMPy-based electrochemical DNA biosensor (1-ECDB) achieves sensitive detection of MDRG, exhibiting a broad linear response range (1.0 × 10⁻¹⁴ to 1.0 × 10⁻⁷ M) and a low detection limit (4.33 fM). Moreover, the 1-ECDB exhibits acceptable specificity, anti-interference capability, reproducibility and long-term stability. Its practical applicability has been validated in diluted human serum samples, yielding recovery rates ranging from 94.2 to 109.2%. This work pioneers the application of POM-conductive polymer composite films in the electrochemical detection of MDRG, bridging the molecular engineering of POMs with biomedical sensing technologies.