Preparation And Application Of Sodium Carboxymethyl Cellulose Terbium(?)/Europium(?) Nanocomposite Fluorescent Probe

Lanthanide fluorescent probes have attracted much attention due to their good fluorescence properties,such as large Stokes shift and long fluorescence lifetime.Manganese ion is the essential trace elements of the human body,but excessive manganese will be harmful to human health.The United States Environmental Protection Agency?EPA?data show that the limit of manganese in drinking water is 0.3mg/L;Acrylamide is a potentially carcinogenic substance to human body,so it is necessary to realize fast and efficient detection of these two substances.In this paper,CMC/Tb???and CMC/Eu???fluorescent probes have been studied on the basis of the fluorescence spectra of rare earth.A new fluorescent probe for detecting Mn²⁺or acrylamide has been successfully constructed.These probes have the characteristics of fast response,high sensitivity and good selectivity.The main conclusions of this paper are as follows:?1?CMC/Tb???and CMC/Eu???fluorescent probes with good fluorescence properties have been successfully prepared with mild and no other organic reagents.These two fluorescent probes show the characteristic fluorescence spectra of terbium???and europium???respectively.Meanwhile,the two fluorescent probes have good optical stability and anti-sedimentation stability,and their fluorescence intensity remains stable after six months.?2?The prepared CMC/Tb???fluorescence probe has good acid and alkaline resistance.The fluorescence intensity of the synthesized CMC/Tb???fluorescence probe can be kept at a relatively high level when the pH value of the solution is kept within the range of 4?10.?3?The fluorescence response of CMC/Tb???fluorescence probe to Mn²⁺can be stable in 1 minutes,show a good performance of rapid response to the detection of Mn²⁺in aqueous solution,and other ions have little interference to the probe for detecting Mn²⁺,show a high selectivity and sensitivity to the detection of Mn²⁺.The detection limit of the probe is 0.046?mol/L,which is fully met the limited standards of 0.3mg/L of EPA.?4?Through the analysis of UV absorption spectra and fluorescence lifetime,the static quenching and dynamic quenching existed concomitantly between Mn²⁺and CMC/Tb???fluorescence probe,which leads to the decrease of fluorescence intensity and even complete quenching of the CMC/Tb???fluorescence probe,and the quenching of ground state plays a leading role.?5?The CMC/Tb???fluorescent paper prepared on the basis of CMC/Tb???suspension has the advantages of good linear relationship,low detection limit and convenient and quick visualization in the detection of Mn²⁺.?6?The prepared CMC/Eu???fluorescence probe can be applied to the detection of acrylamide.there is a good linear relationship between the fluorescence intensity of CMC/Eu???and the concentration of acrylamide in the range of 0.1–100?M.The detection limit is0.085 mu g/L?the signal to noise ratio is 3?.?7?The CMC/Eu???fluorescence probe can specifically detect acrylamide in water based,acidic,alcoholic and fat mimetic food simulants.Among them,the detection limit in alcohol food simulants is the lowest,which is 0.17?g/L and the detection limit of acid food simulants is the highest,which is 0.36?g/L.The fluorescence detection method based on this CMC/Eu???fluorescence probe for the detection of acrylamide has the advantages of simple operation,good selectivity,high sensitivity and good practicality.?8?It is proved that the CMC/Eu???fluorescence probe has high accuracy and precision in the detection of the acrylamide migration in food bag,fresh-keeping film,lunch box and paper cup through the experiment of adding the standard.?9?Through the analysis of UV absorption spectra and fluorescence lifetime,the static quenching and dynamic quenching existed concomitantly between CMC/Eu???fluorescence probe and Acrylamide which resulted in the fluorescence quenching of CMC/Eu???fluorescence probe,and the quenching of ground state played a leading role.