Preparation Of Loaded Fluorescence Chemical Sensor And Its Recognition Of BSA

The load-type fluorescence chemical sensor is a fluorescent sensor which carries a conventional fluorescent compound on a specific carrier by a certain interaction,and performs fluorescence sensing based on a fluorescence response with a recognized substance.This kind of fluorescence sensor can not only improve the fluorescence quenching caused by the aggregation of traditional organic fluorescent compounds,but also improve their photostability and thermalstability,so it has a good application prospect as a new type of fluorescence sensor.In this paper,due to hydrotalcite laminar is positive and the transition metal zinc can be coordinated,zinc-aluminum hydrotalcite(Zn-Al-C03-LDH)can be used as the carrier.8-amino-1,3,6-trisulfonic acid(ANTS)and erythrosine-B(EB)are anion organic dye,which can be loaded on the outer surface of Zn-Al-CO3-LDH and then were used to identify bovine serum albumin(BSA).The main work was divided into two parts:(1)Preparation of ANTS loaded fluorescence chemical sensor and its identification of BSA.Zn-Al-C03-LDH was prepared by coprecipitation method,and ANTS was loaded on the outer surface of the hydrotalcite interlayer in ethylene glycol medium to prepare the LDH-ANTS.The structure and spectral properties were characterized by X-ray powder diffraction,Fourier transform infrared spectroscopy and fluorescence spectroscopy.The results showed that ANTS had no obvious response to BSA.However,when ANTS was loaded on the outer surface of LDH,the product LDH-ANTS had a significant fluorescence enhancement response to BSA.Thus,LDH-ANTS can be used as a fluorescence sensor for identifying BSA to achieve rapid detection of BSA.The fluorescence sensing performance is stable in the range of pH 6.2-7.8.When the concentration range of BSA is 2.5-20.0?g/mL,the recognition is in accordance with Langmuir isothermal adsorption equation and the linear regression equation is:C/I = 0.0002+0.0006C,R2 = 0.9998.The detection limit is 0.03p.g/mL with high sensitivity.The results show that the sensitivity of LDH-ANTS to BSA has a good selectivity and accuracy in a certain range,but it can not be reused.(2)Preparation of EB loaded fluorescence chemical sensor and its recognition of BSA.Zn-Al-C03-LDH was prepared by coprecipitation method.The LDH-EB was prepared by optimizing the reaction time and the addition of EB in ethylene glycol medium.The structure and spectral properties were studied by X-ray powder diffraction,Fourier transform infrared spectroscopy and fluorescence spectroscopy.It was found that the photostability and thermalstability of EB are significantly improved after it was loaded on the outer surface of the hydrotalcite.Before the load,due to electrostatic repulsion,BSA will make EB cluster and then lead to fluorescence quenching;and when EB loaded in the outer surface of hydrotalcite,BSA and EB interacted with each other leading significant fluorescence enhancement and this can achieve rapid detection of BSA.The best use amount of LDH-EB for detecting BSA was 3.5mg/mL and the fluorescence sensitivity was stable in the range of pH 5.8-9.0.The linear regression equation was I=153.20+1.39C,R2=0.9947,and the detection limit was 6.22?g/mL when the BSA concentration range was 10.0-100.0?g/mL.Further study showed that the LDH-EB sensing within a certain range of BSA has good selectivity and accuracy but can not be reused,so it is a disposable sensor.Finally the sensor mechanism of LDH-EB recognizing BSA was proposed.When EB is loaded on the outer surface of the hydrotalcite,the positive charge of the laminates is electrically neutralized with EB anion,which reduces the electrostatic repulsion between EB and BSA.So it is favorable for the BSA anion to move closer to the positively charged LDH-EB surface and the hydrophobic ester groups in EB recognize the hydrophobic sites of BSA,making the distribution of EB more uniform,enhancing the rigidity of the whole system,leading to fluorescence enhancement.All in all,traditional fluorescent compounds such as ANTS or EB are loaded on the outer surface of the interlayer of hydrotalcite,which can not only improve the fluorescence and photostability of the fluorescent compounds,but also develop active products for the effective identification of specific molecules.This provides a new way of thinking to biological fluorescent sensor development.