| Screen printing sweat glucose sensor can effectively channel the diffusion and penetration of sweat on the surface of the fabric and maintain the comfort of the human body,which is expected to overcome the inherent defects of sweat glucose sensor due to the accumulation of sweat in the process of obtaining and collecting sweat and reduce the inherent defects of test stability and sensitivity,with this new blood glucose monitoring method to detect blood glucose in the human body,can reduce the pain of patients,avoid the risk of invasive infection,and has a good market development prospect.Non-invasive blood glucose monitoring has a relatively complete monitoring integrated system,but there is still a lack of clinical trials in its accuracy and reliability,and there are still many problems in improving sensing sensitivity,measurement stability,effective processing of sweat and providing human comfort.At present,the blood glucose detection equipment with textile materials as the substrate is still in its infancy,and most scholars design new textile-based electrode structure glucose detection sensors by borrowing other types of advanced sensor research and development methods,such as fiber,yarn and fabric electrodes,the manufacturing method is cumbersome and the cost is high,and the connection between sensor molding and performance needs more theoretical-experimental exploration.In view of the fact that the materials used in planar fabric-based electrodes are basically similar,but show differences in sensitivity and current response,it is necessary to carry out detailed experiments and elaborate the mechanism of the design schemes of the respective electrodes.In view of the above situation,this project uses fabric as the base,adopts low-cost batch preparation screen printing technology for electrode preparation,optimizes the structure of the designed fabric-based sweat glucose detection sensor electrode,explores the theoretical relationship between the structure and the electrochemical performance of the sensor electrode,analyzes and determines the control method to maximize the performance of the sensor electrode,and simulates the actual application environment for performance verification,and obtains a fabric-based sweat glucose detection electrode with high current response,high sensitivity,wide test range and stable performance.The specific research content and conclusions are as follows:(1)The construction process and performance evaluation of differentiated electrodes on the fabric surface determined that multi-stage pores were the intrinsic reasons for the excellent electrochemical performance of screen carbon current collectors.The carbon current collector structure of fabric base silk screen printing is a key factor affecting its conductivity and electrochemical performance.As a reaction interface,carbon ink can play the role of adsorption collection of ions and electrons,while silver ink mainly acts as a good conductor,which plays a role in rapid transfer of electrons in response,and obtains a low-resistance carbon electrode by controlling the combination of differentiated electrodes,which provides an attachment site for subsequent auxiliary modification substances.The results show that the rich interfacial current collector structure has a certain influence on the conductivity of the electrode,which can promote the adsorption and desorption of electrolyte ions on its surface,concentrate electrons and target substances on the electrode surface,and replenish the redox reaction on the electrode surface,thereby improving the response speed of the electrode to sensitive elements.Determine the optimal number of layers of screen printing electrode during the preparation of 4-layer carbon ink screen printing and 2-layer silver ink screen printing during the preparation of the base electrode;The redox reaction is easier to perform in K3Fe(CN)6 solution of 2.5 m M,which is the best screen printing process for screen printing carbon collector electrode for measuring the concentration of the solution.(2)The assembly molding process and structure optimization of fabric-based detection electrode showed that the synergy of the modified layer and the multi-level structure of carbon collector promoted the electrochemical kinetic process on the electrode surface.By designing the interconnection method of the detection electrode,selecting the fabric substrate with suitable structural density,making carbon electrode in batches,and exploring the optimal deposition parameters of the modified material PB on the basis of the optimal substrate structure and external interconnection structure,the assembly and molding of the fabric-based detection electrode were completed.The results show that the sensitivity and electrical signal response of the detection electrode can be optimized by modifying the layer structure,and the synergistic effect of the thin PB modification layer and the carbon electrode is conducive to promoting the electrode surface kinetic process,so that the fabric-based electrode has an excellent glucose concentration response,and the sensitivity is as high as10.64 μA·m M-1·cm-2(S/N=3).The assembly process of the detection electrode was determined,the gluing interconnection method is conducive to obtaining long-term stable test results,the electrical signal drift is smaller,it has good test stability and durability,the fabric yarn density structure affects the effective area of electron transfer in the electrochemical process of the electrode,the electrochemical effective area of the fabric structure electrode with a number of warp and weft yarns of 350 per square inch is the largest,and the electrode structure of 4 turns PB by CV deposition can promote the electrode surface of the electrode and ion diffusion and accelerate the interfacial electrochemical reaction rate.(3)The simulation of fabric-based electrodes in sweat proves their wide detection range,high sensitivity response,and good repeatability stability.Through 10 blank sample tests,the range of effective glucose detection of the best structure electrode was determined;Using artificial sweat as the electrolytic test solution,multiple I-T repeat tests and multi-day fixed-point I-T tests were used to simulate the specific scenario application of electrochemical fabric sensing electrodes for sweat glucose monitoring and multiple repeated tests within one day and multiple days to evaluate the feasibility of electrode application in sweat.The results showed that the glucose stability and accuracy test range of the fabric-based sweat glucose detection electrode prepared by the experiment was 0.8-250 μM,which met the detection of trace glucose in sweat.The electrode can be tested at least 5 times in sweat and still maintain a high glucose response sensitivity of up to 79.17 μA·m M-1·cm-2;It can maintain a high sensitivity response to glucose for at least 72 hours at room temperature.In summary,this paper proposes a structural optimization technology and mechanism of the sensitivity and electrical signal response intensity of fabric-based sweat glucose electrode by constructing sweat glucose detection electrode on the surface of fabric,which provides a certain theoretical basis for the research and development of sweat glucose sensing electrode,and the established screen printing process and assembly molding method are conducive to the batch and low-cost production and industrialization process of this type of glucose electrode. |
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