Study On Constructing Heavy Ion And Dopamine Sensor Based On MOFs

Heavy metal pollutants such as lead(Pb²⁺)and cadmium(Cd²⁺)in water have concealment and irreversibility,which have serious harm to human health.Iron(Fe³⁺)is one of the essential trace elements in the human body,which is very important for maintaining human health.Too much or too little iron in the human body can cause some diseases.Dopamine as a neurotransmitter in the human body plays a vital role in the human nervous system.Its content is closely related to life and work,but when the content is too low,it will also affect the health of the human.Therefore,it is still of great significance to explore the detection of the substances.Metal-organic frameworks?MOFs?have good application prospects as electrode materials because of their advantages of large specific surface area and adjustable pore size.UiO series materials belong to MOFs and are stable in water,so the materials can directly modify the glassy carbon electrode to construct an electrochemical sensor for detecting heavy metal ions and dopamine in water.MOFs materials have different properties by adjusting different linking ligands,the experiments designed and synthesized MOFs with fluorescent properties and constructed a fluorescence sensor for the detection of Fe³⁺.The main contents are as follows:?1?UiO series materials were synthesized by the solvothermal method.The materials directly modify the electrode to construct an electrochemical sensor for detection lead(Pb²⁺)and cadmium(Cd²⁺)in water.The result shows that UiO-67/GCE has the best electrochemical response and it can well distinguish Pb²⁺and Cd²⁺.Under the optimal conditions,the linear range and detection limit of both cadmium and lead ions were analyzed.Furthermore,testing the adsorption amount of Pb²⁺and Cd²⁺by UiO-67,the possible mechanism was explored.The results showed that the surface of Pb²⁺and Cd²⁺to the UiO-67/GCE was adsorbed and controlled by Langmuir adsorption.Applying the sensor to actual water sample analysis and achieving satisfactory results?2?The MIL series and UiO series materials with different metal centers were synthesized by a solvent method,and construct an electrochemical sensor to dopamine.The result shows that MIL-101?Cr?/GCE and UiO-67/GCE has the best electrochemical performance.Under the optimal conditions,the linear range and detection limit of dopamine response of the sensor constructed by two modified materials were tested.The experimental results show that the difference of metal centers can lead to the difference of electrochemical behavior.Choosing the metal center of suitable MOFs can improve the performance of the sensor and provide a new idea for optimizing the sensor.?3?Zinc is a metal center and H₂NDI and H₂BDC are two linking ligands.A new MOFs material with fluorescent properties of a double ligand is synthesized by hydrothermal method.The structure of X-ray single crystal diffraction is a two-layer interpenetrating structure.The experiments study the fluorescence performance of the different solvent sand different metal ions;the result shows that Iron ions(Fe³⁺)can cause fluorescence quenching.