Research on Sensitive Fluorescence Detection of Fe³⁺ and Cr₂O₇ ^2- in River Based on Ln-MOF Materials

Abstract Excessive release of Fe 3+ and Cr 2 O 7 2- would threaten public health and environmental safety. Seeking an effective probe for Fe 3+ and Cr 2 O 7 2- sensing by a simple and rapid approach in real water samples is significantly desirable. Herein, Eu-MOF for monitoring Fe 3+ and Cr 2 O 7 2- were obtained and characterized by PXRD, FT-IR spectroscopy and luminescence spectroscopy. The study showed that Eu-TDA exhibited high sensitivity, special selectivity, and strong stability for Fe 3+ and Cr 2 O 7 2- detection. The limit of detection for Fe 3+ and Cr 2 O 7 2- were as low as 2.43×10 -6 and 3.26×10 -6 M, respectively. The fluorescent detection method was used for actual water samples from Songhua River, which obtained satisfied recovery from 98.84% to 106.22%.