Controlled Preparation Of Prussian Blue And Its Application In Colorimetric Detection

Prussian blue has been widely used ever since it was discovered.Prussian blue is a hexacyanoferrate with a face-centered cubic structure.Its morphology can be changed and controlled,and Prussian blue is easy to be surface modified.By changing and modifying the morphology of Prussian blue,its specific surface area can be increased,more active sites can be provided to enhance its peroxidase activity,and its electrochemical activity and photothermal effect can be changed.Prussian blue has obvious absorption peak in the near infrared window,and its excellent photothermal effect can significantly increase the temperature under laser irradiation.So it can be used in biomedicine,in photothermal therapy.Prussian blue has good peroxidase activity and can be used for the colorimetric detection of hydrogen peroxide.At the same time,the Prussian blue solution is blue,which makes it of high potential value in the application of colorimetric detection.Colorimetry is widely used for detection because it is intuitive.Prussian blue can be used for the colorimetric detection of biological small molecules and metal ions.Small biological molecules are crucial in metabolism.The discharge of metal ions into rivers will pollute water resources and damage the ecological environment.Therefore,it is of great significance to detect biological small molecules and metal ions by colorimetric method.Based on the above contents,this paper mainly focuses on changing the morphology of Prussian blue.And increase its peroxidase activity.Hydrogen peroxide and glucose were detected by colorimetric method.And Prussian blue was modified by histidine(HisPB).Silver ions were detected by colorimetric method according to the effect of Prussian blue modified with histidine on silver ions in different pH solutions.The main research contents are as follows:(1)the effects of reaction time,temperature,protective agent and reducing agent on the morphology of Prussian blue were investigated.By controlling the experimental conditions,the hydrothermal synthesis of mesoporous hollow Prussian blue was improved.The synthesis method is simpler and easier to operate than the traditional one.The detection of hydrogen peroxide in low concentration range was realized.Glucose oxidase was loaded with mesoporous hollow Prussian blue for the colorimetric detection of glucose.(2)Prussian blue modified by histidine was synthesized.Histidine will react with silver ion in acidic environment,and the peroxidase activity of HisPB will be reduced.The silver ion was detected by the colorimetric method by measuring HisPB peroxidase activity.Histidine will not react with silver ions under alkaline conditions.But Prussian blue can react with silver ions in an alkaline environment,and the absorption of Prussian blue decreases after the reaction.The stability of Prussian blue modified by histidine in alkaline solution was significantly improved.So HisPB can be used to detect silver ion concentration in alkaline environment.The two methods verify each other and improve the accuracy of silver ion detection.