NH2-MIL-53(Al) nanocrystals: a fluorescent probe for the fast detection of aromatic nitro-compounds and ions in aqueous systems

Abstract

NH₂-MIL-53(Al) nanocrystals were successfully fabricated by an improved solvothermal route at 120 °C for 24 h without the addition of any surfactants or capping agents, employing AlCl₃·6H₂O and 2-amino terephthalic acid (NH₂-BDC) as the initial reactants, and N,N-dimethylformamide (DMF) and water with a volume ratio of 5/25 as the mixed solvent. The as-obtained product was characterized by XRD, FESEM and FTIR. Under the excitation of 380 nm UV light, the as-obtained NH₂-MIL-53(Al) nanocrystals displayed strong fluorescence emission. It was found that some aromatic nitro-compounds (ANCs) or ions in aqueous systems could strongly quench the above fluorescence, indicating that the as-obtained NH₂-MIL-53(Al) nanocrystals could be made into a fluorescent probe for the detection of ANCs and ions in aqueous systems. Simultaneously, the mechanism to cause fluorescence quenching was discussed.