Study On The Biomarkers Detection Methods Based On Hydrogen-bonded/metal Organic Framework Nanozymes

As a new type of porous crystalline material,hydrogen-bond organic frameworks（HOF）not only has the features of high surface area,permanent porosity and periodic integration,but also have the advantages of mild synthesis condition,solution processability,and easy regeneration.These merits enable HOF to be a tunable platform for the building of functional materials.Beyond that,HOF materials possess biocompatibility and low toxicity attributed to the metal-free property of components,giving them great potential for application in the field of biosensing.However,due to its low stability stability,strong rigidity,and lack of modified functional groups,difficult to functionalize of HOF.Nanozymes are of particular interest due to their enzyme-mimicking activity and high stability that are favorable in biosensing and immunoassays.Therefore,preparing porous multifunctional nanozymes via simple and practical methods to reduce the cost of production and promote their performance in as-mentioned aplications,along with exploring their mechanism of the formation of porous structure and catalysis,have their meaning in both scientific research and future applications.On the basis of the above consideration,this thesis proposes to construct a series of multifunctional nanoenzymes based on HOF materials,metal-organic frameworks（MOF）materials and other nanomaterials through non-covalent interactions,and applications in the field of colorimetric immunosensors.Major findings are as following.In the first part,we described a mild synthetic approach for construction of stable photosensitizer HOF through combination of the multiple hydrogen bondingπ-πinteractions as well as the residual hydrogen donor/acceptor groups.The excess carboxyl group（-COOH）on the surface of the HOF and the amino-groupα-Bungarotoxin nucleic acid aptamer（NH₂-b-BGT-apt）form an amide bond（-CO-NH-）by chelating agent to construct a conjugated bioprobe.Therefore,colorimetric biosensor is constructed by the HOF to detect ofα-Bungarotoxin（α-BGT）.The proposed sensing platform was successfully used to determineα-BGT in human serum samples.In the second part,the metal-bonded organic frameworks（HOF@Cu-MOF）was synthesized via a solvent-thermal method possess a porous core-shell structure and high specific surface area,obtaining a new,simple and practical methods and route for the preparation of multifunctional nanozymes.HOF@Cu-MOF has peroxidase and laccase activity,and its peroxidase activity is 9.6 times higher than that of natural horseradish peroxidase,and laccase activity is 11.3 times higher than that of natural laccase.By using the obtained HOF@Cu-MOF as nanozymes,a dual-signal colorimetric biosensing platform was developed for the sensitive determination ofβ-BGT,and the biosensing detection ofβ-BGT was successfully applied to human serum samples.In the third part,a Fenton-type metal peroxide nanomaterial was in situ on the HOF surface to construct the HOF-Cu O multifunctional nanozymes.HOF-Cu O was used as an activatable agent for enhanced peroxidase by self-supplying H₂O₂.Thus,colorimetric biosensing is constructed by the HOF-Cu O to realize the detection of neutrophil gelatinase–associated lipocalin（NGAL）.The proposed colorimetric sensing platform can be used for the detection of NGAL in human serum samples.