This study introduces a novel polyoxometalate (POM) heterostructure designed to address challenges in ultratrace analysis and sensor stability. Supercritical anti-solvent and hydrothermal methods are employed to fabricate a composite that enhances stability, sensitivity, and selectivity for cysteine (Cys) detection. The optimization of inter-component interactions and improved dispersibility contributes to superior stability and longevity. These preparation techniques increase the total oxygen vacancy density, which facilitates the migration of surface oxygen vacancies and promotes the electrocatalytic process. Additionally, tuning the band structure effectively suppresses electron–hole recombination, thereby enhancing catalytic capability. The integration of potassium phosphotungstate (KPW) as an electron transport mediator results in a stable “point-surface” loading structure, increasing active sites and improving the material's specific surface area and catalytic efficiency. The Cu/Zr nanoparticle-grafted KPW composite (CZPW) demonstrates excellent performance, achieving an ultratrace detection limit of 30.6 pM and a broad linear detection range from 50 pM to 1 mM. Overall, this study elucidates the mechanisms of supercritical preparation and its impact on electrocatalytic Cys reactions, providing valuable insights into the development of highly effective and stable biosensors.

中文翻译：

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通过超临界反溶剂法合成具有增强金属-载体相互作用的富氧空位 POM 异质结构用于超痕量半胱氨酸分析


本研究介绍了一种新型多金属氧酸盐 （POM） 异质结构，旨在解决超痕量分析和传感器稳定性方面的挑战。采用超临界反溶剂和水热法制备复合材料，以提高半胱氨酸 （Cys） 检测的稳定性、灵敏度和选择性。优化组分间相互作用和提高分散性有助于实现卓越的稳定性和使用寿命。这些制备技术增加了总氧空位密度，从而促进了表面氧空位的迁移并促进了电催化过程。此外，调整能带结构可有效抑制电子-空穴复合，从而增强催化能力。磷酸钾 （KPW） 作为电子传递介质的整合产生了稳定的“点表面”负载结构，增加了活性位点并提高了材料的比表面积和催化效率。Cu/Zr 纳米颗粒接枝 KPW 复合材料 （CZPW） 表现出优异的性能，实现了 30.6 pM 的超痕量检测限和 50 pM 至 1 mM 的宽线性检测范围。总体而言，本研究阐明了超临界制备的机制及其对电催化 Cys 反应的影响，为开发高效和稳定的生物传感器提供了有价值的见解。