2D-MOF Nanozyme Sensor Arrays For Probing Phosphates And Enzymatic Hydrolysis

Phosphates exist in various forms,including adenosine monophosphate(AMP),adenine nucleoside diphosphate(ADP),adenine nucleoside triphosphate(ATP),pyrophosphate(PPi),and orthophosphate(Pi).These phosphates play important roles in biological processes,such as cell signaling,energy metabolism,etc.Particularly,phosphates can be interconverted under the catalysis of corresponding enzymes.These interconversion processes release high energy,which not only was the basis of cell activities,but also was directly related to cell signaling,metabolism,and various diseases.To better understand the phosphates and their reaction mechanisms,researchers have established various detection systems for phosphates.However,these systems could only detect a certain type of phosphate and they could not effectively identify and discriminate various phosphates.Sensor array can solve this problem well.In recent years,with the rapid development of functional materials,sensor arrays based on fluorometric and colorimetric signals have been extensively applied in the field of bioanalysis.In some cases,sensor arrays could also be used to monitor the enzymatic processes.Inspired by these successes,a series of two-dimensional metal-organic frameworks(2D-MOFs)with peroxidase-mimicking activity were synthesized and colorimetric sensor arrays for phosphates were constructed in this thesis.The discrimination of phosphates by the established sensor array was studied and the identification of blind samples was established.The sensor array was also applied to probe the interconversion processes between phosphates catalyzed by natural enzymes.In this thesis,a series of 2D-MOF materials were synthesized by a self-assembly method.Their sizes,crystal structures,and morphologies were characterized by dynamic light scattering(DLS),X-ray diffraction(XRD),and transmission electron microscope(TEM).Future,we verified that the synthetic 2D-MOFs had good peroxidase-like activity.Due to the strong bindings between phosphates and metal ions,the structure of the 2D-MOFs collapsed when phosphates interacted with 2D-MOFs,resulting decreased peroxidase activity.Experiments verified that different phosphates had differential inhibition effects on the peroxidase-like activity of 2D-MOFs.A three-channel colorimetric sensor array for phosphates was constructed based on 2D-MOFs nanozymes,which could discriminate phosphates effectively.To better demonstrate the applications of the sensor arrays,we further validated the ability of the sensor array for identifying phosphates under practical conditions.Combining with the traditional molybdenum blue colorimetric method,we established a practical detection system for identifying blind phosphate samples.Based on the discrimination ability of the sensor array for phosphates,we further applied it to probe the interconversion process of phosphates catalyzed by natural enzymes,which broadened the bioanalysis application of nanozymes.