Establishment And Evaluation Of Medical Blood Glucose Monitoring System Based On Electrochemical Glucose Sensor

The detection of glucose based on electrochemical oxidation of glucose is of great importance in clinical medicine due to the glucose electrochemical oxidation is easily to be transferred into current signal. The glucose concentration is a significant guiding index for the routine surveillance of diabetes and on-line monitoring of peritoneal dialysis since the glucose concentration indicates the personal health level of carbohydrate metabolism in the body. For blood glucose determination, the primary detection methods in the world today are "hexokinase?HK?"method and "glucose oxidase?GO? "method. The application of HK with the use of automatic biochemical analyzer leads to accurate results but takes too long. However, the GO is mainly applied in the second generation of glucose sensor-"portable blood glucose meter" because it can satisfy the clinical screening purposes and be used in daily self-examination for its rapid and real-time feedback.The kinetics studies shown that the electro-oxidation of ascorbic acid or uric acid on electrode is a diffusion-controlled process, while the electrocatalytic oxidation of glucose is dynamic controlled relatively. That provides a way to improve the detection selectivity by a well-designed electrode with rough and porous structure. A sensor of NiOOH/Ni?OH?₂@C electrode was fabricated by the following process:metallic Ni and carbon powder were simultaneously electroplated onto Ni wire by the composite plating method with the help of cationic surfactant, followed by electrochemically oxidation of Ni to Ni?OH?₂ in alkali medium. SEM and XRD results showed that shell-core structure of Ni@C could be formed by simply control the ratio of Ni2+ and carbon powder. The high electrochemical activity and high specific surface area of the fabricated NiOOH/Ni?OH?₂@C electrode lead to good performance in detecting glucose:sensitivity of 11.84 mAcm-2mM^-1, good linearity ?R²=0.99995?in range of 0.05mM?10mM with detection limit of 10-6M?D=3S/N?. The specific structure of the electrode also made the sensor display excellent parallelism and good selectivity to glucose when uric acid and ascorbic acid co-existed in the simulated serum sample.