Research On The Non-enzyme Glucose Electrochemical Sensor Based On Cobalt Hydroxides

Diabetes is a chronic disease characterized by abnormal blood glucose level in the body.In recent years,it has become one of diseases that seriously endanger public health.It is of great significance to monitor the daily blood glucose level of millions of diabetic patients.In many detection methods,glucose biosensor with glucose oxidase as the core is characterized by high sensitivity and good selectivity,which is the mainstream product of glucose biosensor market.However,the further development of enzyme glucose sensor is hindered due to the strict requirements of enzyme on environmental conditions and the high cost of fixed technology,and non-enzyme glucose sensor is favored by researchers.As an active material for enzyme-free glucose sensors,precious metal materials have excellent catalytic activity,but their large-scale application is limited by their low natural reserves and high costs.The transition metals such as copper,nickel and cobalt with high abundance and low cost have shown excellent electrocatalytic oxidation ability,showing a great potential to replace precious metals as electrode materials for enzyme-free glucose sensor.In recent years,cobalt hydroxides have shown excellent electrocatalytic oxidation ability due to their inherent catalytic activity and good stability.The main work of this paper is to study the properties of cobalt hydroxides as electrode material of enzyme-free glucose sensor.We used solvothermal method to grow cobalt hydroxides on the foamed nickel,constructed Co HS/Ni Foam and its doped Co Ni HS/Ni Foam and Co Fe HS/Ni Foam,and investigated their ability to catalyze glucose oxidation and their practical significance as electrode materials for enzyme-free glucose sensors.The main contents of this paper are as follows:1.using foamed nickel as self-supporting conductive substrates,granular and lamellar cobalt hydroxides were prepared by solvothermal method,and cobalt hydroxide/nickel foam working electrode was constructed.Two-dimensional lamellar cobalt hydroxide has better electrocatalytic oxidation ability than granular cobalt hydroxide in water medium.2.the composite structure of cobalt hydroxide nanosheets and nickel foam was used as electrode material for glucose enzyme-free sensor,and its ability to catalyze glucose oxidation was investigated in alkaline solution containing glucose.The results show that the sensitivity of the sensor is 3904?A·m M^-1·cm^-2,the linear range is 0.2?3.6 m M,the detection limit is 0.017m M(S/N=3),the response time is less than 1s,and it has good anti-interference and stability.3.using foamed nickel as self-supporting conductive substrates,cobalt hydroxide nanosheets were prepared by solvothermal method,and different proportion of nickel or iron elements were added in the synthesis process,and cobalt-nickel double hydroxide and cobalt-iron double hydroxides glucose enzyme-free sensor were constructed.The experimental results show that doping nickel or iron transition metal elements can improve the electrocatalytic oxidation ability of cobalt hydroxides,in which doping 10%nickel or 50%iron element has the best effect.