Studies On Glucose Biosensor Based On New FAD-dependent Glucose Dehydrogenase

Glucose biosensor is the common tool of blood glucose monitoring.The accuray performance is very important,which maybe cause the influences on the evaluation of diabetes status and treatment program.However,current blood glucose monitoring products are still suffered from the influences by the paritial pressure of oxygen,other saccharides,endogenous reducing substances in the blood sample,and so on.Therefore,it is necessary to develope new glucose biosensor with better accuracy performance,better assay specificity and less influence from the operation.This thesis used new FAD-depedent glucose dehydrogenase without xylose interference as reaction enzyme to improve assay specificity and eliminate the effect of the oxygen tension(p02)in the blood sample.The technical hurdles of electrochemical signals and interference from reducing substances were focused.In addition,a biosensor and measurement algorithm were designed to eliminate the risk of inaccuracy results because of insuffficent sample.Main results are summarized as below:1)Based on FAD-dependent glucose dehydrogenase without xylose interference,new glucose biosensor was developed.The combination of 2,6-Dichlorophenolindophenol and hexaammineruthenium(?)chloride was used as the double-mediator.The formulation was optimized and the linearity pefornance of sign respond was good.The influecnes of oxygen tension of blood sample,the interference of xylose and uric acid were tested,Compared with the current products,glucose biosensor developed showed less influence of p02 of blood sample,xylose,and uric acid,and then it would break through the limitations of current products and reduce some risk due to misusing.2)A biosensor with measurement algorithm was designed for insufficient sample detection.The results show that new design could effectively recognize the insufficient sample and give the corresponding "error" message,and then eliminated the risk of inaccuracy results due to insuffient sample.For the sample between insufficient and sufficient status,new biosensor could recognize some measurement with accuracy results and give right results,and give "error" message for the measurement with inaccuracy result risk.Compared with the existing technology,new design can reduce some unnecessary waste for the condition between insufficient and sufficient sample,and eliminate the possibility of inaccuracy results.In addition,new design also provides a possibility for reducing the minimum sample volume.In this thesis,new glucose biosensor based on FAD-dependent glucose dehydrogenase without xylose interference was developed,and the measurement algorithm for insufficient sample detection was designed.New technology would improve the accuracy,assay specificity,and anti-influence from substances and operation factors for glucose biosensor.