Construction of BSA-CuNCs@UiO-66 nanoprobe based on MOF confinement effect and its ultrasensitive fluorescence sensing for creatinine.

This study employed a pore-confined synthesis strategy to achieve the in situ growth of bovine serum albumin-capped copper nanoclusters (BSA-CuNCs) within the UiO-66 framework (BSA-CuNCs@UiO-66). This nanocomposite enables highly sensitive and specific detection of creatinine (CR). Results demonstrated that the spatial confinement imposed by UiO-66 induced aggregation of the BSA-CuNCs and suppressed non-radiative transitions, leading to an approximately 10-fold enhancement in fluorescence intensity and a 11-fold increase in quantum yield. Leveraging the specific adsorption and enrichment capability of the UiO-66 framework toward CR, the BSA-CuNCs@UiO-66 fluorescence probe exhibited significant fluorescence quenching upon exposure to CR, achieving a detection range of 50-1000 nM and a detection limit of 30.81 nM. This work presented a novel confinement engineering strategy utilizing metal-organic frameworks (MOFs), establishing a new design paradigm for high-performance fluorescence probes with significant potential in bioanalytical applications.