Research On Paper-based Electrochemical Biosensing Based On Catalase-like Enzyme Nanomaterials

In recent years,with the rapid development of science and technology,biosensors developed based on bioanalysis technology,as an efficient analysis strategy,have displayed the advantages of high sensitivity,low detection limit,good stability,little damage to biomolecules,and online continuous monitoring in complex systems.It obtains a broad application in many fields such as food detection,environmental protection and disease diagnosis.Cellulose paper with unique biocompatibility,easy to functionalize,easy to fold and other characteristics,is widely used as the base of manufacturing various sensors.At this point,paper-based biosensors emerge at the right moment,providing new possibilities for the accurate detection of a variety of diseases.Here,in order to meet the needs of early diagnosis and clinical prognosis monitoring of major diseases,the paper-based electrochemical biosensors based on catalase-like enzyme nanomaterials are designed and prepared with the help of the intrinsic porous structure and easy functionalization of cellulose paper and the electrocatalytic performance of nanomaterials.By improving the conductivity of paper base and preparing catalase-like enzyme inorganic nanomaterial signal probes with high electrocatalytic performance,the dual output strategy of electrochemical and colorimetric signals can be obtained to achieve rapid and sensitive detection of different disease markers.The main work is as follows:(1)The copper-cobalt double-doped Ce O2 nanospheres with high catalytic performance are synthesized by hydrothermal method and introduced to the surface of functional paper fiber through hybridization chain reaction to construct the sensing interface of paper chips.With the help of copper-cobalt double-doped Ce O2 nanospheres,hydrogen peroxide is catalyzed to achieve electrochemical signal amplification.Meanwhile,the copper-cobalt double-doped Ce O2 nanospheres can catalyze the oxidation of 3 3’ 5 5’-tetramethylbenzidine in the presence of hydrogen peroxide,thereby realizing of the electrochemical/colorimetric double pattern detection of mi RNA-155 in the paper-based biosensor.(2)Pd@ZIF67/ZIF8 core-shell catalase-like enzyme nanomaterials are synthesized by hydrothermal method,and Pd@ZIF67/ZIF8 with high catalytic activity is introduced to the paper substrate with the help of three-dimensional network structure through antigen-antibody specific recognition,obtaining electrochemical signal amplification output and improving electrochemical response ability.By virtue of the wax printing technology,the paper-based hydrophilic/hydrophobic integrated functional areas are achieved.The oxidation of the chromogenic agent by hydrogen peroxide,the self-cleaning and electrochemical/colorimetric dual-mode detection of PSA are realized by adjusting the three-dimensional folding structure of paper chips.(3)Based on the three-dimensional porous structure of paper fibers,Bi2S3@Mo S2 nanoflowers are grown in situ as the signal transmission layer to obtain electrochemical amplified signals via its catalase-like activity.Screen printing and wax printing techniques are used to divide functional areas of paper chips.The flow of fluid is controlled by capillary action,and octahedral Ce O2 nanomaterials are introduced to regulate the electron transfer process at the sensing interface,further amplifying the electrochemical signal.The octahedral Ce O2 nanomaterials are released to the colorimetric region by double-chain specific nuclease,and the electrochemical/colorimetric double sensitive detection of mi RNA-141 is realized via its catalytic capacity.