Abstract：In this study, flexible dual-mode sensor with fast fluorescence and electrochemical dual responses to Al³⁺ and pH was obtained by synthesizing Eu-MOF on carbon fiber substrate using a simple solvothermal method. The prepared dual-mode sensor exhibits excellent performance in detecting Al³⁺, the electrochemical method demonstrates a wide detection range from 1 nM–1 M with a low detection limit of 0.36 nM. The fluorescent method exhibits a linear range from 10 μm to 100 mM and 100 mM–1 M with a detection limit of 2.84 μM. Meanwhile, the pH sensor reveals a good changing trend R² = 0.995 for fluorescent detection and R² = 0.958 for electrochemical detection from pH 3 to 7. Importantly, the proposed dual-mode sensor demonstrates excellent selectivity, stability, and specificity in the detection of Al³⁺. The detection mechanism of dual-mode sensors has been proposed. This Eu-MOF dual-mode sensor has achieved the ultrasensitive and accurate analysis of Al³⁺ and pH in tap water and different beverages. In addition, synthetic Eu-MOF can be used for wet spinning and preparation of anti-counterfeiting inks to broaden its applications. Overall, the proposed dual-mode sensor increases the reliability of detection and exhibits great potential in the fields of environmental analysis, food safety and smart wearables.