Dual-mode fluorescent/electrochemical sensors based on Eu-MOF@carbon fiber for Al3+ and pH detection

In this study, flexible dual-mode sensor with fast fluorescence and electrochemical dual responses to Al 3+ 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 Al 3+ , 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 R 2 = 0.995 for fluorescent detection and R 2 = 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 Al 3+ . The detection mechanism of dual-mode sensors has been proposed. This Eu-MOF dual-mode sensor has achieved the ultrasensitive and accurate analysis of Al 3+ 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. • The Eu-MOF/carbon fiber was fabricated by using one-pot solvothermal method. • The flexible sensor can perform fluorescence/electrochemical dual-mode detection of Al 3+ and H + . • The dual-mode sensor demonstrates high selectivity, cycling stability and repeatability. • This dual-mode sensor can be accurately and reliably applied in actual samples. • The MOF materials prepared can be used for wet-spinning luminescent fibers and luminescent inks.