Preparation And Physicochemical Properties Of Starch-based Fluorescent Materials

In this paper,ultrasonic synthesis and 1,3,5,and 7 days pea starch were used as raw materials to study the preparation of fluorescent materials by acid hydrolysis of starch granules and the optimal conditions for the application of fluorescent materials.Spectral properties,fluorescence quantum yield,scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),elemental analysis(EDS),Fourier transform infrared(FTIR),etc.The physicochemical properties of the fluorescent materials were compared with the possible luminescence of fluorescent materials.The main results are as follows:1.The hydrolysis degree of pea starch treated with ultrasonic acid hydrolysis for 1,3,5,and 7 days were 53.84%,64.66%,73.79%,and 88.00%,respectively,indicating that ultrasonic treatment caused some damage to the starch structure and increased the sulfuric acid content.Contact surface area,as the acid hydrolysis time increases,the starch particle size gradually decreases.2.The fluorescein was prepared by nitric acid refluxing for acid hydrolysis for 7 days.Nitric acid concentration,refluxing time,reflux temperature,and solution pH were the main factors affecting the fluorescence intensity of the preparation.Response surface optimization results showed that 2 mol/L nitric acid was refluxed.The temperature was 110 °C reflux 2.5 h,the solution pH3.5,the fluorescence intensity of 440.313.3.The fluorescein was dialyzed and dried by oxidative fluorescence solution.The effects of buffer pH,ratio of fluorescent solution and different excitation wavelength on the fluorescence intensity were studied.The response surface was used to optimize the optimal application conditions.The results showed that the solution pH was 4 Fluorescent material(g): citric acid buffer(mL)solution = 0.03:10.The optimal excitation wavelength is 330 nm.The fluorescence intensity of the prepared fluorescent material is 469.342.This condition is the best application condition.4.Under the optimal conditions of acidolysis,pea starch was hydrolyzed for 1,3,and 5 days,respectively,and the fluorescence intensity was compared with that of the fluorescent material.The results showed that the longer the acid hydrolysis time,the greater the fluorescence intensity of the prepared fluorescent material.Therefore,the fluorescence intensity of the fluorescent material is related to the degree of acid hydrolysis of the starch;the fluorescence quantum yields of the fluorescent material prepared from 1,3,5,and 7 days of acid hydrolysis are 6.10%,6.56%,6.60%,and 7.27%,respectively.5.By fluorescence spectrometry,we can know that different temperature and illumination time have less influence on the fluorescent material,indicating that the fluorescent material has higher temperature resistance and optical stability,and its surface is also rich in hydrophilic groups such as carbonyl and carboxyl groups.,Soluble in water,so in the cell,living imaging and other research has potential applications.The experimental fluorescent material with starch as carbon source has better luminescence stability and biocompatibility,and the material has amorphous shape,which has potential application value in the field of bioimaging.