Application of CD and Eu³⁺ Dual Emission MOF Colorimetric Fluorescent Probe Based on Neural Network in Fe³⁺ Detection

Abstract

A new highly uorescent hybrid material (CD@Eu-MOF) was synthesized by encapsulating CD (Carbon Dots) prepared from citric acid and ethylenediamine on the basis of a metal-organic framework prepared from Eu 3+ and 1,2,4-benzenetricarboxylic acid. The prepared composite not only maintains the excellent uorescence properties of CD and Eu 3+ respectively, but also forms a dual-emission uorescence system, and the system has good stability in aqueous solution. It was further used as a novel uorescent probe for the detection of Fe 3+ , which can effectively exclude the interference of other metal ions from the detection, and the intensity ratio of I Eu /I CD of CD@Eu-MOF material has a good linear relationship with Fe 3+ in the range of 1-200 μM. In this study, computer vision and BP (Back Propagation) neural network were used to train and t the sample data, and it was veri ed that the actual uorescence color of CD has a good linear relationship with Fe 3+ concentration. In addition, the BP neural network also veri ed that the uorescence spectrum data of CD@Eu-MOF also has a good linear relationship with Fe 3+ concentration.This study provides a new method for the fabrication of ratio and colorimetric Fe 3+ uorescence sensors, and provides a feasible solution for the simple and visual detection of Fe 3+ in the environment.

Preparation of biomass water‐soluble carbon quantum dots and their application in Cr (VI) ions detection

“…As shown in Figure 4C, after being placed for 1, 10 and 20 days, the fluorescence intensity of the CQDs solution remained basically unchanged, the solution was still clear and transparent, and no precipitation occurred. According to this, the CQDs we synthesized still have strong stability under the interference of salt solution, pH and sunlight, which can make up for the defects of previous research 16,22 …”

“…In order to explore the practicability of CQDs sensor, we further carried out a real addition and recovery experiment with reference to previous research 15,16 . For the experiment of Cr 6+ addition and recovery in actual water samples, tap water samples in the laboratory and Xinghu lake water samples from Wuhan university were selected as experimental water samples, and the lake water samples were filtered with a 0.22 μm microporous membrane.…”

“…In order to explore the practicability of CQDs sensor, we further carried out a real addition and recovery experiment with reference to previous research. 15,16 For the experiment of Cr 6+ addition and recovery in actual water samples, tap water samples in the laboratory and Xinghu lake water samples from Wuhan university were selected as experimental water samples, and the lake water samples were filtered with a 0.22 μm microporous membrane. The tap water and lake water samples were prepared with 0.5 mg/mL CQDs solutions, respectively, and different amounts of Cr 6+ were added to them to ensure that the concentrations of Cr 6+ in the final samples were 0, 20, 40 and 60 μM, respectively.…”