Research Of Glucose Sensors Based On Carbonized Silk Fabric

Diabetes is a common metabolic disease,which has a wide range of patients and poses a great threat to human health.In the diagnosis and treatment procedure of diabetes,the most important indicator is the blood glucose concentration.Glucose sensors,as analytical systems for efficient detection of blood glucose concentration,have therefore received more and more attention.The working electrode of the glucose sensor is usually composed of base materials and active substances.The conventional base materials are usual y commercial electrodes or made by depositing precious metal on insulating base materials.The surface structures are relatively simple,the modification methods are thus limited,and the stability may be insufficient.For the active substances,those of the conventional sensors are often prepared separately and then adhered to the surface of the electrode using a binder.This often leads to insufficient contact between the active material and the test substance,and the electrical signal cannot be efficiently transmi tted to the electrode substrate,leading to the relatively low sensitivity of the entire sensorIn order to solve the above problems,in this paper,a highly efficient glucose sensor substrate material is prepared by carbonizing silk fabric and then modifying with carbon nanotubes.Compared with the conventional substrate materials,the obtained material has better conductivity and more complex surface structure,higher stability and flexibilit y,and the self-supporting structural system make it potential for abundant modifica t io n means.Using the above material as the substrate,according to the characteristics of the second to fourth generation glucose sensors,a variety of enzyme-containing or enzymefree sensors were constructed.In order to construct an enzyme-containing sensor,the surface of the substrate material was modified with Prussian blue and platinum microspheres,and glucose oxidase was then loaded to fabricate the second generation glucose sensor MWCNT/CSF-PB/GOx and the third generation glucose sensor MWCNT/CSF-Pt/GOx.The study found that due to the good conductivity,rich microstructure and other advantages of the platinum microspheres,the third-genera t io n sensor MWCNT/CSF-Pt/GOx glucose sensor should have good sensitivity in comparison with the second-generation sensor MWCNT/CSF-Pt/GOx.In the construction of the fourth-generation enzyme-free glucose sensor,the cosintering method and the electrodeposition method are used to avoid the use of the binder,thereby maximizing the sensitivity of the glucose sensors.Due to the limitations of the preparation method,it is hard to further improve the respond ability of the sensor,and the stability of cuprous oxide itself is relatively inadequate.As for the electrodeposited MWCNT/CSF-Cu sensor,due to the surface modification of the carbon nanotubes,the sensor showed a higher sensitivity,and the active material copper showed higher stabilit y.Finally,the influence of working conditions on the response process was studied.It was found that the pH and working temperature of the electrolyte had a significa nt influence on the sensor response procedure,while the salt concentration(taking NaCl as an example)had almost no effect on the sensor response current.