Construction Of Sensing Interface Based On Two-dimensional Nanomaterial Titanium Carbide And Its Application In Disease Marker Detection

Biomolecules such as hydrogen peroxide（H₂O₂）,dopamine（DA）and uric acid（UA）are closely related to human life activities.The abnormal content of these biomolecules represents the abnormal changes of a certain metabolic process and some physiological activities or physiological active substances in the human body,which can be used as disease markers to determine the health status of the body.Therefore,efficient and accurate detection of related disease markers is of great significance in the rapid diagnosis of diseases and the exploration of life processes.Current detection technologies for disease markers have various drawbacks.Since disease markers are usually present in very low concentrations and mixed with various proteins or other biomolecules,their specific detection becomes difficult.Therefore,we need to develop new tools to detect disease markers to solve the above problems.In recent years,sensing technology has the advantages of rapidity,portability,reusability,simple operation and high sensitivity,and has been widely used in the detection of disease markers.At present,the key issue for the preparation of disease marker sensors is how to construct a sensing interface with high electrical activity and good stability,which can be applied to real-time monitoring of single or multiple disease biomolecules.The research shows that the application of novel two-dimensional nanomaterials to sensing technology can be used to solve this key problem,and the construction of the sensing interface based on many novel two-dimensional nanostructures can realize the efficient detection of relevant disease markers.Two-dimensional transition metal carbide-titanium carbide（Ti₃C₂）,as a new type of two-dimensional transition metal sheet semiconductor material,possesses high specific surface area,abundant surface functional groups and specific binding with different disease biomarkers to meet different analytical purposes strong potential.Therefore,we constructed an efficient and stable sensing interface for disease biomarkers by integrating the sensing technology with a novel two-dimensional nanomaterial Ti₃C₂ to solve the problem that the content of H₂O₂ is too low in vivo and that uric acid and dopamine were easily absorbed by ascorbic acid in serum.Interference is difficult to achieve specific detection and other problems.However,few-layer Ti₃C₂ nanosheets suffer from the disadvantages of being prone to curling and being easily oxidized under positive potentials, resulting in a decrease in detection activity,which limits their full application in the detection of disease biomarkers.In response to the above problems,we introduced nitrogen atoms into Ti₃C₂ to prepare nitrogen-doped Ti₃C₂ with a rough pore structure,which is not easy to curl,and there is no oxidation peak under positive potential,which realizes the ultrasensitive detection of H₂O₂ and specific detection of uric acid and dopamine at positive potential.The research work carried out in this paper is mainly as follows:（1）The silver nanozyme sensor supported by few-layer and multi-layer Ti₃C₂nanosheets realizes ultrasensitive detection of H₂O₂.The differences in surface functional groups of Ti₃C₂ materials with different thicknesses of multilayer organ-shaped and few-layered sheets were explored,and the effect of surface functional groups of Ti₃C₂ on the morphology and dispersion state of the loaded silver nanozyme was investigated.Ag material is the electrode modification material to detect H₂O₂ respectively.By comparison,it is found that the silver nanozyme supported by few-layer Ti₃C₂ is smaller in size,more uniformly dispersed and regular in shape,showing higher catalytic activity.Finally,the sensor prepared based on few-layer Ti₃C₂-loaded silver nanozyme successfully realized the real-time monitoring of H₂O₂ released by breast cancer cells,so the sensor has the potential to be a tool for real-time monitoring of the oxidative stress state of cancer cells.（2）The few-layer Ti₃C₂ material has good electrical conductivity and better catalytic activity of the supported silver nanozyme,but it is prone to curling and easy oxidation,which leads to the degradation of sensor performance.In response to this problem,this paper uses safe and non-toxic dopamine as nitrogen source,and adopts the method of high temperature carbonization to successfully introduce nitrogen into Ti₃C₂,and prepare a new type of nitrogen doped with unique pore structure,high conductivity and good stability.Hetero Ti₃C₂ material was used as a new excellent carrier for silver nanozymes,and a unique three-dimensional flower-like silver nanostructure was grown on its surface by electrodeposition.The composite material showed better H₂O₂ detection performance,with wide linear range（0.05-35 m M）and the lower detection limit（1.53μM）of H₂O₂ were successfully achieved in real samples such as serum,tap water,contact lens care solution,etc.,proving that it was a potential rapid on-site disease diagnosis and environmental monitoring.（3）Taking advantage of the high catalytic activity and good conductivity of nitrogen-doped Ti₃C₂ materials,a sensing interface based on this material was successfully constructed for simultaneous detection of dopamine and uric acid in the presence of largeπstacking interaction enhance the ability of the electrode to simultaneously detect dopamine and uric acid in a neutral environment.High-dose ascorbic acid with reducing and weak acidity can promote the redox process of dopamine and uric acid.The sensor effectively solves the interference of ascorbic acid on dopamine and uric acid in real serum samples and the easy oxidation of Ti₃C₂ under positive potential.problems,indicating that it has the potential to be practically applied to the rapid diagnosis of clinical metabolic diseases and neurodegenerative diseases.