دانلود رایگان مقاله کمپلکس هیدروژل با گود بی حرکت مغناطیسی برای سنسور گلوکز

Abstract

A fiber optic glucose biosensor based on Poly(N-isopropylacrylamide-co-acrylamide) (P(NIPAAm-co-AAm))-magnetic-immobilized glucose oxidase (GOD) complex (PMIGC)was fabricated to perform the controllable detection of glucose by changing temperature. The complex was prepared by combining P(NIPAAm-co-AAm) with GOD immobilized on Fe3O4@SiO2(F)@meso-SiO2 nanoparticles using in-situ complex method. Since P(NIPAAm-co-AAm) has the lower critical solution temperature (LCST) of 36 °C, at the temperature above LCST, P(NIPAAm-co-AAm) shrank and PMIGC could not catalyze the oxidation of glucose. At the temperature below LCST, P(NIPAAm-co-AAm) swelled and catalysis occurred. Because of this temperature sensing characteristics of PMIGC, the temperature controllable detection of glucose can be carried out by the biosensor. The optimal detection conditions for this biosensor were achieved with pH6.5, 35 °C and 12 mg of GOD amount. At 25 °C, a good linear relationship between Ͽ, the phase delay change of the sensor head, and the glucose concentration in the range of 50⿿700 mg/dL (2.78⿿38.89 mmol/L) was observed, the detection limit was 8.33 mg/dL (0.46 mmol/L) (S/N = 3). This linear graph can be defined by the equation of y = 0.01463 + 0.0003313x, R2 = 0.9914. The biosensor has the characteristics of good repeatability and selectivity, and can be used for the glucose detection in practical samples.

4. Conclusion

PMIGC was prepared and the controllable catalysis for the oxidation of glucose was realized by using it. Based on PMIGC, a fiber optic glucose biosensor was fabricated to perform the controllable detection of glucose by changing temperature. The optimal detection conditions for this biosensor were obtained. At 38 ◦C, PMIGC could not catalyze the oxidation of glucose and the biosensor was unable to perform the determination of glucose. At 25 ◦C, a good linear relationship between and the glucose concentration in the range of 50–700 mg/dL was observed. This biosensor has the characteristics of good repeatability, selectivity and can be used for the determination of glucose concentration in practical samples, showing a promising prospect for practical application. Furthermore, by using PMIGC and immobilized COD and controlling the detection temperature, it will be possible to perform simultaneous determination of glucose and cholesterol. This work is currently undertaking in our laboratory.