Metal-organic framework-based composite nanomaterials usually exhibit synergetic properties of their components leading to new functionalities and can be used for a wide range of applications. In this study, we designed and synthesized an amine-CQDs@UiO-66 composite fluorescence sensor by integrating amine-functionalized carbon quantum dots (amine-CQDs) and the zirconium-based metal-organic frameworkUiO-66 using a post-synthetic modification approach (PSMA). Herein, UiO-66 was used as an adsorbent to capture and enrich the target molecules selectively and the amine-CQDs were employed as a functional monomer to selectively and sensitively sense the bonding interactions between UiO-66 and the target molecules, andfurther transduce these chemical events into detectable fluorescence signals. The resulting amine-CQDs@UiO-66 sensor exhibited excellent fluorescence selectivity and sensitivity toward 4-nitrophenol (4-NP) because of the immobilized highly fluorescent amine-CQDs. The fluorescence sensitivity was increased because of the enrichment of 4-NP that originated from the well-defined microporous MOF. Moreover, 4-NP could be detected in a wide concentration range of 0.01–20.0 μM with a detectionlimit as low as 3.5 nM. To the best of our knowledge, this work presents the first combination of the fluorescence functional monomer amine-CQDs with the favorable properties of MOFs by PSMA for selective fluorescence sensing. We fabricated amine-CQDs@UiO-66 composites via a post-synthetic modification approach, incorporating amine-functionalized carbon quantum dots functional monomers that could respond to the analyte 4-nitrophenol (4-NP). We found it to be highly selective and sensitive for 4-NP, detecting this species even in mixtures of metal ions and other phenols. Display omitted •Amine-CQDs@UiO-66 composites were prepared via post-synthetic approach.•Amine-CQDs@UiO-66 composites were found to be excellent FL probes for 4-NP detection.•Amine-CQDs@UiO-66 composites have high selective sensing performance for 4-NP.