Abstract Fluorescent Co(II)-based MOFs, [Co2(Bpy)(Oba)2], nanoflakes were successfully synthesized via a (NH4)6Mo7O24∙4H2O assisted hydrothermal route at 180 °C for 12 h, employing Co(NO3)2∙6H2O, 4,4′-Oxybis(benzoic acid) (Oba) and 4,4′-Bipyridine (Bpy) as the initial reactants. The as-obtained Co-MOFs nanoflakes were characterized by XRD, FESEM, and FTIR. It was found that the presence of (NH4)6Mo7O24∙4H2O could markedly promote the formation of Co-MOFs nanoflakes. The PL studies showed that as-obtained Co-MOFs nanoflakes emit a violet light at 440 nm under the UV light excitation of 297 nm; and that the morphology of Co-MOFs did not affect the PL intensity. Interestingly, the fluorescence of as-obtained Co-MOFs nanoflakes was highly sensitive to vanillin, an important food additive, and could be selectively quenched by vanillin in aqueous systems. Simultaneously, the fluorescence quenching mechanism was discussed.

中文翻译：

---

钼酸铵辅助形状控制合成荧光 Co(II) 基 MOFs 纳米薄片作为高灵敏度探针用于选择性检测奶粉中的香草醛

摘要 采用 Co(NO3)2，通过 (NH4)6Mo7O24∙4H2O 辅助水热路线，在 180 °C 下，12 小时，成功合成了荧光 Co(II) 基 MOF，[Co2(Bpy)(Oba)2]，纳米薄片∙6H2O、4,4'-氧双(苯甲酸) (Oba) 和 4,4'-联吡啶 (Bpy) 作为初始反应物。所获得的 Co-MOFs 纳米薄片通过 XRD、FESEM 和 FTIR 进行表征。发现 (NH4)6Mo7O24∙4H2O 的存在可以显着促进 Co-MOFs 纳米薄片的形成。PL 研究表明，所获得的 Co-MOFs 纳米薄片在 297 nm 的紫外光激发下发出 440 nm 的紫光；并且 Co-MOF 的形态不影响 PL 强度。有趣的是，所获得的 Co-MOFs 纳米薄片的荧光对香兰素高度敏感，香兰素是一种重要的食品添加剂，并且可以在水性体系中被香兰素选择性猝灭。同时讨论了荧光猝灭机制。