Design And Performance Study Of Carbon Materials-based Non-enzyme Glucose Molecularly Imprinted Electrochemical Sensors

Diabetes and its complications caused by chronic hyperglycemia have drawn worldwide attention all the time,while glucose is one of the most important biological species for diagnosing diabetes.Additionally,glucose is a common reactant and intermediate product in microbial fermentation,one of the most important indicators needed to be controlled during fermentation,which directly related to the yield and quality of product.Therefore,the determination of glucose is of great significance for the treatment of diabetes and other diseases and the control of industrial production.Currently,the application of enzymatic glucose electrochemical sensor in the market is subject to the influence of external conditions such as temperature,pH value and humidity,which make the enzyme vulnerable to inactivation.And the immobilization process of enzymes is complex and expensive.The research of non-enzymatic electrochemical sensor with high sensitivity,high selectivity and stability has important academic value and wide application prospect.In this paper,carbon materials with large specific surface area and good conductivity are used to combine with molecularly imprinted polymer that owned specific recognition function for target molecules to design non-enzymatic glucose molecularly imprinted electrochemical sensor,and the performances are studied,the main contents are as follows:1.Nano-carbon quantum dots(CDs)were synthesized from biomass material as carbon source.It was modified to surface of glassy carbon electrode(GCE)surface by mixing with chitosan(CS)solution that owned good film-forming properties.After that,MIP layer was synthesized on CDs-CS/GCE using a three-electrode system in the polymer solution with 3-aminobenzoboric acid(APBA)as the functional monomer and glucose as the template molecule.MIECS was obtained after electrochemical elution of the template.Experimental conditions were optimized.The characterization and performance of MIECS prepared under optimal conditions were studied,and the results showed that the MIECS could detect glucose in the linear range of 0.5~40 ?M and 50~600 ?M,the detection limit was 0.09 ?M(S/N=3).Inaddition,the sensor also showed good selectivity,reproducibility and stability,meanwhile,was successfully applied to the detection of glucose in human serum samples.2.By means of dealloying technique,the GCE was firstly deposited in the solution containing nickel sulfate and copper sulfate,and the porous hollow nickel nanospheres(HNiNS)layer was electrodeposited on the electrode surface by constant potential method to obtain HNiNS/GCE.After that,CDs-CS in the previous chapter was modified to HNiNS/GCE,MIP layer was prepared by cyclic voltammetry(CV)electropolymerization,and MIECS with specific recognition of glucose was obtained after the template molecules were removed,its characterization and performance were studied.Results showed that the MIECS prepared under optimal conditions could detect glucose in the linear range of 0.03~10 ?M and 20~300 ?M,the detection limit was 4.6 nM(S/N=3).In addition,the sensor also showed good selectivity,sensitivity,reproducibility and stability.The proposed MIECS has been successfully applied to the detection of glucose in human serum samples and fermentation samples.3.Boric acid functionalized carbon quantum dots(APBA-CDs)were prepared with sodium citrate and aminophenylboric acid as precursors.Glucose and APBA-CDs were combined by boron affinity,in the presence of functional monomer tetramethoxysilane(TMOS)and phenyltriethoxysilane(TEOS),MIP was obtained by sol-gel polymerization.MIP was coated on GCE and then template molecule removed by electrochemical elution.MIECS possessing double selective recognition of glucose owing to boron affinity and molecular imprinting were synthesized.The characterization and performance of MIECS prepared under optimal conditions were studied,and the results showed that the MIECS could detect glucose in the linear range of 0.005~8 mM,the detection limit was 1.0 ?M(S/N=3).In addition,the sensor also showed excellent selectivity,reproducibility and stability,meanwhile,was successfully applied to the detection of glucose in human serum samples.