Studies On Novel Electrochemical Sensor And Its Application On The Detection Of Obesity Biomarker And Active Components In Traditional Chinese Medicine

As an endocrine metabolism disease,obesity not only affects the body shape,but also causes a variety of complications.In addition,some people already hidden dangers of obesity（such as fatty liver,etc.）even if it looks the opposite,which are serious threats to human life and health.Therefore,there is an urgent need to propose a quick and easy analytical method for the quality identification of obesity biomarkers.In addition,the highly sensitive electrochemical sensing of active components has attracted more and more attention from drug analysts due to the complexity of the composition of traditional Chinese medicine.Electrochemical sensors,an emerging analytical tool,focus on the simplicity and portability of detection,while reducing the cost of preparation,reducing the amount of sample,saving detection time,reducing patient suffering,and making it more convenient and practical.In this paper,the excellent conductivity electrochemical materials and immobilized biomolecules as sensitive element,and electrodes as transducers.Through chemical reaction between target analyte and sensitive components converted into an electrical signal to sensitive analysis and detection.The main research contents of this thesis are as follows:1.Novel nanomaterial of porous graphene functionalized black phosphorus as electrochemical sensor platform for bisphenol A detectionBisphenol A is a chemical that can cause obesity and severely harm the functions of various organs of the body.In order to achieve its sensitive and rapid determination,the porous graphene and black phosphorus can form P-C bond under strong coupling to realize the encapsulation protection of black phosphorus.Porous graphene functionalized black phosphorus composite（BP-PG）with good stability,high conductivity and large specific surface area was successfully prepared by infrared drying method.A porous graphene functionalized black phosphorus electrochemical sensor was constructed by immobilizing the composite on the surface of bare glassy carbon electrode.The PG-BP had been characterized by infrared spectroscopy,Raman,X-ray photoelectron spectroscopic,scanning electron microscopy and energy dispersive spectrometer.The redox mechanism of bisphenol A in the electrochemical response process was discussed.Under the optimal conditions,the BPA detection current has a good linear relationship in the range of 4.3×10^-8-5.5×10^-5 mol/L with a detection limit of 7.8×10^-9 mol/L（S/N=3）.The sensor is used to realize the trace analysis of bisphenol A in human daily necessities and biological samples,and also expands the application of black phosphorus in the field of electrochemistry.2.Porous graphene-black phosphorus nanocomposite modified electrode for the label-free detection of marker of non-alcoholic fatty liver:leptinThe change of in vivo concentration of leptin has important clinical significance for the diagnosis of obesity and its related complications.In this study,The study utilizes the excellent conductive synergistic enhancement of porous graphene and black phosphorus composites,using porous graphene functionalized black phosphorus nanomaterials as substrate modification materials,and using gold nanoparticles,cysteamine,and glutaraldehyde for layer assembly for the leptin antibody firmly fixed in the surface of the electrode.Finally,a immunosensor based on porous graphene functionalized black phosphorus nanomaterials was constructed for the sensitive detection of leptin and the sensor has a minimum detection limit of 0.036 pg/mL.3.A novel way for analysis of calycosin in Astragalus membranaceus and Radix Hedysari via polyaniline functionalized graphene quantum dots fabricated electrochemical sensorPolyaniline functionalized graphene quantum dots composite with excellent performance was successfully prepared by situ polymerized,and it was applied to fabricate electrochemical sensor for analysis of calycosin in the complex samples of traditional Chinese medicine.The sensor was characterized by infrared,Raman,SEM and TEM.Under the optimized conditions,the analysis of calycosin in Radix Hedysari and Radix Astragali by differential pulse voltammetry,which displayed acceptable reproducibility,long-term stability,good selectivity and sensitivity.