Ti₃C₂T_x Modified Paper/fabric Based Electrochemical Sweat Sensors

With the rapid development of modern technology,medical flexible wearable electronic devices continue to emerge.Among them,portable and highly integrated human sweat detection devices have fully proven their application value in medical and human health related fields.However,modern wearable sweat detection devices pay little attention to the sweat accumulation on the human-machine interface and the impact of the wearable device on the safety and comfort of human skin.Continuously produced sweat accumulates on the surface of the sensor’s high-strength polymer substrate（PET,PDMS,etc.）,which reduces its accuracy,immediacy and sensor service life,and the skin problems caused by long-term accumulation of sweat are also worrying.Therefore,while maintaining high sensitivity and stability,effective processing of sweat and providing human comfort have become new requirements.In response to the above problems,this paper prepared an electrochemical sweat sensor for real-time sweat composition monitoring,and tried a variety of flexible substrate sweat sensors for the feasibility of human health monitoring.Using Ti₃C₂T_x,Ti₃C₂T_x/polyaniline as electrode modification materials and methylene blue as the electronic medium,a flexible paper-based/fabric-based electrochemical sweat sensor was constructed.Study the microfluidic effect of sweat in paper-based sensors and the performance comparison of different fabric-based sensors.The details are as follows:A paper-based sensor electrode with a double-layer structure was prepared by a combination of wax printing and screen printing technology.Ti₃C₂T_x and methylene blue materials were modified on the electrode surface using a drop coating method,and glucose oxidase and lactate oxidase were modified to obtain specificity Glucose and lactate sweat sensor with recognition function.Because Ti₃C₂T_x material has good active area and high conductivity,it is not only conducive to the immobilization of enzymes on the electrode surface,but also can improve the electron transmission capacity of the electrode surface and play a signal amplification effect.Methylene blue acts as an electronic mediator to promote charge transfer and synergistically improve the electrochemical performance of the sensor electrode.On this basis,modifying specific oxidases can accurately detect changes in the content of lactic acid and glucose in human sweat.The best performance Ti₃C₂T_x and methylene blue in the above chapter are the electrode modification materials,and the dual-channel electrochemical sweat analysis sensor based on cellulose paper is further integrated.The device includes a paper-based device with microfluidic function,a set of glucose and lactate sensors with good sensing performance,and a signal processing chip for Bluetooth transmission.The well-designed paper-based three-dimensional diffusion path can effectively collect sweat in a short time and quickly diffuse it from the man-machine interface in the vertical direction.Wearing this dual-channel paper-based electrochemical sweat sensor on the upper arm of the subject for cycling test can more accurately reflect the changes in the content of lactic acid and glucose in the subject’s sweat.The low-cost and convenient two-channel paper-based electrochemical sweat sensing system is expected to be further practically applied in the fields of non-invasive electrochemical sensors and wearable bioelectronic products.Compare the properties of different fabric materials and analyze the feasibility of its application in wearable sweat sensors.Nylon fabric is selected as the final construction of the electrochemical sweat sensor,and Ti₃C₂T_x/polyaniline（PANI）material is synthesized to modify the electrode surface,and the methylene blue electronic mediator synergistically improves the electron transmission efficiency of the sensor.Nylon-based electrochemical sweat sensor can be used to detect the change of glucose content in human sweat.Because Ti₃C₂T_x/PANI composite nanomaterials have good electrical conductivity and biocompatibility,the macromolecular structure of PANI materials is more conducive to the immobilization of biological enzymes on the electrode surface.Combining it with Ti₃C₂T_x can improve the electron transmission capacity of the electrode surface and further improve the sensor sensitivity.