Research Of Implantable Continuous Glucose Minimally Invasive Sensor

With the change of lifestyle and the acceleration of aging population,diabetes has gradually become one of the chronic non-communicable pandemics that seriously threaten human life and health.Peripheral blood testing for blood sugar is the most widely used method.But continuous blood glucose monitoring system(CGMS)can provide more comprehensive information on blood glucose concentration and fluctuations,which is significant for the treatment and prevention of diabetes.Currently,glucose sensor as an important component in determining the core performance of CGMS has poor monitoring performance and stability,which limits application in many people with diabetes.Aiming at the existing problems of sensor,such as small sensing area,lack of oxygen,high production cost and complex implantation operation,a method to enhance the performance of stainless-steel needle electrode based on platinum nanoparticles was proposed.Then,according to the influence factors of electrodeposition,the three-factor three-level orthogonal experiment was designed to research the optimal conditions of platinum deposition.Test results in vitro showed that the glucose sensor modified by the optimal deposition conditions of platinum nanoparticles could basically achieve linear monitoring of 0-20 mm,but the average sensitivity was low,only 39.75 n A/m M.In order to improve the sensitivity of the above sensor,this paper studied the effect of outer membrane on the sensors performance,then a sandwich hierarchically porous membrane with oxygen supplement function(SHPM-OS)for implantable glucose sensor was proposed to optimize the performance of glucose sensor,which could improve the average sensitivity and response time to 109.38 n A/m M and 5s respectively while maintaining the same linear test range.In addition,the relative sensitivity of SHPM-OS sensor remained above 90% in the first 10 days.Therefore,the SHPM-OS outer membrane could basically achieve the goal of optimizing sensor sensitivity,and had good fast response time and stability which meet the needs of continuous glucose monitoring.In order to apply the SHPM-OS sensor to the continuous monitoring of individual users,the portable control and detection circuit was designed and manufactured based on the monitoring performance of SHPM-OS.Test results showed that the control and detection circuit could drive the sensor normally reactions and achieve signal acquisition within the range of 100 n A-3 u A.After integration with the SHPM-OS sensor,the portable monitoring system could basically achieve the detection of glucose concentration in 0-20 m M,and the repeatability error of system was lower than 10%.Therefore,the SHPM-OS sensor could be a key component of CGMS system in the future.