Fabrication And Properties Research On The Glucose Selectivity And Potassium Ion Selectivity Electrode Based On QCM

In recent years,with the change of people’s living habits and lifestyles,the incidence of diabetes in the world has risen sharply.Currently,diabetes has seriously threatened human health and is the fourth largest killer after cardiovascular and cerebrovascular diseases,cancer and respiratory diseases.Diabetes cannot be cured,patients need to monitor the blood glucose concentration throughout life,and given the necessary treatment according to blood glucose concentration.Studies have shown that real-time monitoring of blood glucose,can effectively control blood sugar levels,and reduce the incidence of hypoglycemia.Therefore,it is very significant to study the new glucose detection method,and it also has a very high application value.Potassium detection is critical in monitoring imbalances in electrolytes and physiological status.The development of rapid and robust potassium sensors is desirable in clinical chemistry and point-of-care applications.As an extremely sensitive mass sensor,quartz crystal microbalance is highly sensitive,capable of responding to changes of trace substances on the surface of quartz wafer.With the development of QCM technology in the liquid phase,QCM sensors are increasingly used for the detection of biological fluids.Based on quartz crystal microbalance sensor technology,glucose selective electrode and potassium selective electrode were fabricated by surface modification of quartz crystal to achieve rapid,real-time and accurate detection of glucose and potassium ions.The main research contents include:（1）Adopting multi-walled carbon nanotubes（MWCNTs）as the substrate and aminophenylboronic acid as the selective unit,combining aminophenylboronic acid with oxidized MWCNTs.It was then coated onto a gold electrode to make a glucose-selective electrode.From the experimental results,we successfully prepared a glucose-sensitive electrode based on QCM sensor.The selective electrode can achieve rapid and accurate determination of glucose in human physiological conditions（pH7.0-7.5,blood glucose range 1.1-33.3 mmol/L）,The selective electrode has good reproducibility for glucose detection,good selectivity to other sugars such as fructose,maltose,ribose,lactose,xylose,sucrose,galactose.It provides a new method for continuous monitoring of blood glucose.（2）We synthesized potassium ion-sensitive electrode through surface-initiated polymerization using three different monomers:acrylamide,polyethylene glycol methacrylate（PEGMA）,and（2）-allyloxymethyl 18-crown-6-ether.The potassium ion-sensitive electrode exhibited rapid response and high selectivity to K⁺ions when compared with other cations,such as Na⁺,NH₄⁺,Mg²⁺,and Ca²⁺.The detection range for K⁺ions sensing varied from 0.5 to 7.0 mmol/L,covering the physiological concentration range.More importantly,the hydrogel revealed potential reusability.