碱性体系无酶电化学葡萄糖传感器
Alkaline System Electrochemical Glucose Sensor
Electrolyte: NaOH or KOH, 0.1M, 50mL
Glucose Solution: 1, 10, 100, 1000mM
1. Contrast the reaction with or without glucose substrate
CV
Scan Rate: 50mV/s
Window Potential: adjustable
Glucose Solution: with or without 1mM
2. Compare whether the electrode surface conforms to the diffusion law under different scanning rates
CV
Scan Rate: 4, 9, 16, 25, 36,49, 64, 81, 100mV/s
Window Potential: adjustable
Glucose Solution: 2mM
3. Compare the reaction of different glucose concentration at the same scanning rate on the electrode surface
CV
Scan Rate: 50mV/s
Window Potential: adjustable
Glucose Solution: 0, 5, 10, 50, 100, 200, 400, 600, 800, 1000μM (adjustable)
4. Determination of optimal reaction potential
IT
Time: 500s
Potential Setting: 0.4, 0.45, 0.5, 0.55, 0.6V (adjustable)
e.g.
1. Use IT to flatten the curve, and then wait for 200s. In the 200s, the concentration of glucose solution in the electrolyte will increase by 1mM every 50s. (Drop 50μL glucose solution, which can be ignored for 50 mL electrolyte system)
2. The optimal reaction potential should be comprehensively considered in terms of LOD (current noise), linear range and sensitivity (response current).
5. Determination of glucose sensor sensitivity
IT
Time: 2500s
Potential Setting: use the results of step 4
e.g.
1. Use IT to flatten the curve, and then wait for 200s. In the 200s, the concentration of glucose solution in the electrolyte will increase by 1μM every 50s (0-10μM); 10μM every 50s (0-10μM); 100μM every 50s (0-10μM); 1000μM every 50s (0-10μM).
2. Fitting points on step current is sensitivity.
3. S/N=3, LOD=3*σ/s (σ≈0.03, s=sensitivity).
6. Test the selectivity of glucose sensor to glucose
IT
Time: 1000s
Potential Setting: use the results of step 4
e.g.
1. Use IT to flatten the curve, and then wait for 200s. In the 200s, Drop Glucose, Lactose, Sucrose, Fructose, Urea, Nacl, Kcl, Ascorbic Acid, Uric Acid, Dopamine and Glucose, respectively, into the electrolyte system.
2. This step is to determine whether the interfering substance will affect the sensor. Other types of interfering substances can be replaced according to different applications.
7. Test the stability of glucose sensor
IT
Time: 1000s
Potential Setting: use the results of step 4
Glucose Solution: 0.2mM (adjustable)
e.g.
1. At the best test potential, record the current density on the first day, and then record it every 3 days, 8 times in total.
2. Take the response current of the first day as the reference, and use all the data as the percentage point graph.
8. Real engineering sample test
IT
Time: 300s
Potential Setting: use the results of step 4
e.g.
1. Use IT to flatten the curve, and then wait for 200s. In the 200s, Drip real engineering samples, such as blood, sugary drinks, etc. Then, observe the response potential and bring it into the sensitivity formula. Compare the glucose concentration based on sensitivity with the real glucose concentration.
2. If you need human or experimental animal samples, please pass the approval of the Scientific Ethics Committee.
