In-situ growing Eu-MOF on TEMPO-oxidized cellulose nanofibers to form fluorescent films for Fe3+ detection

Metal-organic frameworks (MOFs) are porous hybrid materials made of metal and organic linkers. Combining MOFs with polymers enhances their performance and addresses the issue of low stability. In this study, a uniform nanoscale Eu(III)-based metal-organic framework (Eu-MOF) was synthesized and grown in situ on TEMPO(2,2,6,6-tetramethylpiperidinyl-1-oxide)-oxidized cellulose nanofibrils (TOCNF), resulting in the formation of Eu-MOF@TOCNF fluorescence films through vacuum filtration. These films exhibited favorable mechanical properties, high transmittance, and stable fluorescence characteristics within the pH range of 3–11. The film produced the characteristic emission peak of Eu 3+ , recognized the selective quenching of Fe 3+ within 0–100μM, and displayed an inverse relationship between fluorescence intensity at 616 nm and Fe 3+ concentration. This approach holds significant promise for Fe 3+ detection in solutions and offers a novel strategy for developing highly efficient optical sensors based on fluorescence specificity.