Research On Glucose Sensor Based On Prussian Blue Composite Membrane Modified Electrode

As a chronic disease that is difficult to cure,the incidence of diabetes is increasing,and prevention and monitoring are effective ways to control its onset.Traditional glucose test strips that need fingertip blood collection for testing can cause pain and cause anxiety.Therefore,research on low-cost,high-sensitivity and simple-to-make non-invasive glucose sensors is important to improve the prevention and control of diabetes.With the development of nanomaterial sensitization technology,electrochemical glucose sensors based on nanocomposite modified electrodes have become a research hotspot.In this study,Prussian blue nanoparticles（PBNPs）with carbon-based materials/conductive polymers were used to fabricate glucose sensors,and a non-invasive glucose sensor based on sweat detection was targeted because of the correlation between sweat and blood glucose concentration.The main contents of this thesis are as follows:（1）PBNPs were prepared by a two-component co-precipitation method by adding a dispersant to make them carry a positive charge,while carboxylated carbon nanotubes（MWCNT-COOH）are negatively charged,and at the two-phase interface of xylene/water,the above two substances use the positive and negative charges to attract each other to form a composite film in a self-assembled manner.Chitosan（CS）was used to immobilize glucose oxidase（GOx）on the surface of the composite film,and perfluorosulfonic acid-based polymer（Nafion）was used to encapsulate it to form a glucose sensor based on PBNPs/MWCNT-COOH composite film.SEM,XRD and UV-Vis were used to characterizing the microscopic features of the electrode,and electrochemical workstation analyzed electrode performance and glucose electrocatalysis.Electrochemical workstation analyzed the electrode performance and glucose.The results showed the sensor has a wide detection range（0.01-1 mM）,good sensitivity(11.87μA·mM^-1·cm^-2)and low detection limit（7μM）.（2）Given that graphene nanoflakes（GNFs）and poly（3,4-ethylenedioxythiophene）（PEDOT）synergistically can provide more electrochemically active sites and faster charge transfer rates.First,we prepared GNFs thin films using the Marangoni effect.Then,PBNPs and PEDOT were co-deposited on the surface of GNFs films to construct glucose sensor based on GNFs/PBNPs/PEDOT composite films.It was shown that the electrode material has a large specific surface area,good wettability and redox activity,and the prepared glucose sensor achieved a detection range of 0.005-1 mM,sensitivity of 40.9μA·mM^-1·cm^-2,detection limit of 1μM,response time of 4.5 s,and verified its excellent stability,repeatability and selectivity.（3）Design of a metal mask for three-electrode patterning,and three regions of the silicon substrate were vacuum vaporized with Au and Ag to form a miniature electrochemical sensing chip,with the Au region forming the working electrode and counter electrode and the Ag region chlorinated to form the Ag/AgCl reference electrode.It has good electrocatalytic performance for glucose,which has a greater development prospect and can be applied to the field of wearable sensors in the future.