Preparation Of Amino Acid-based Fluorescent Probes And Identification Of Heavy Metal Ions In Waste Water

The heavy metal pollution in industrial wastewater has brought great hidden dangers to environment and people’s health.Therefore,it is important to find efficient detection technology of heavy metal ions.Fluorescent probes are an effective means for detecting heavy metal ions for their advantages of fastness,convenience and high sensitivity.In this study,series of Eu and N droped fluorescent probes were synthesized with amino acid deep eutectic solvents（DESs）as precursor.In the application of water quality monitoring,it was demonstrated an effecitive fluorescent probe for the heavy metal ion detection.The contents are as follows:A fluorescent probe（L-Glu/Gly/EuCl₃·6H₂O）was synthesized from L-Glutamic acid（L-Glu）,glycerol（Gly）and EuCl3·6H2O to detect metal ions in the industrial wastewater.The influence of external factors such as time,pH and temperature on the stability of the fluorescent substance were investigated.The physical and chemical properties of the fluorescent substance were characterized.The heavy metal ions detection process was explored.It was found that L-Glu/Gly/EuCl3·6H2O fluorescent probe showed obvious fluorescence quenching effect after adding Fe³⁺solution,thus could be used to detect Fe³⁺in the industrial wastewater.N-doped carbon quantum dots（N-CQDs）were prepared by hydrothermal method with L-arginine（L-Arg）,Gly,Urea as raw materials.The effects of amino acid species,DESs composition,and ratio of materials on the fluorescence properties of CQDs were studied,respectively.The optimal excitation wavelength and the emission peak of the N-CQDs fluorescent probe was 245nm and 405nm.The photoluminescence mechanism of fluorescent probes was studied by the interaction of metal ions with fluorescent probes.With L-Arg/ethylene glycol（EG）/Urea as precursor,N-CQDs were prepared by hydrothermal method.The influence of hydrothermal time,the amount of urea,placement time,temperature and pH on the fluorescence intensity were investigated,respectively.The optimal excitation wavelength and the emission peak of the N-CQDs fluorescent probe was 250nm and 415nm.