Preparation And Study Of Performance Of Glucose Sensing Electrode

Glucose as the main substance of physical energy, plays a very important role in humanbody. With the improvement of human living standards, the population of the diabetes isincreasing rapidly every year and it has evolved into a global issue of affected human health.Meanwhile, glucose is of great significant in the research fields of medical diagnosis, foodindustry and biotechnology. In recent years in the research of glucose sensor, enzymatic glucosesensor has good selectivity and sensitivity developed earlier, but its development and applicationrestrictions as the characteristic of the enzyme. Therefore, it is great necessary to develop asimple, practical and sensitive non-enzymatic glucose sensor. There are a large number ofarticles of non-enzymatic glucose sensor have been reported already.As is known to all, photoelectrochemical detection has the advantages of simpleness, quickresponse, efficiency and so on, which makes it widely used in variou fields. Copper and itsoxides have relatively cheap, stable performance, easy preparation and goodphotoelectrochemical catalysis performance to glucose, which makes copper and its oxide andphotoelectrochemical detection combined very well for the detection of glucose.Molecular imprinting technology (MIT) is a technique to design artificial receptors with apredetermined selectivity and specificity for a given analyte. The artificial receptors can be usedas ideal materials in various application fields. In recent years, due to its predetemination,practicability and recognition, molecular imprinting has developed rapidly. MIT is based on theformation of a polymerization between an analyte (template) and a functional monomer. Then,the template is removed from the polymer leaving specific recognition sites. Thus, the resultantpolymer recognizes and binds selectively only the template molecules.The thesis is including the following two parts:1.Copper/copper oxide modified n-silicon electrode for glucosephotoeletrochemical detectionThe system is based on a semiconductor silicon(n-n+-Si electrode). Platinum(Pt, front),copper(Cu, front) and aluminum(Al, back) layer were successively coated on n-n+-Si (111) wafers (Cu/Pt/n-n+-Si electrode) by vacuum evaporating technique. A stable layer of CuO wasformed(Cu-CuO/Pt/n-n+-Si electrode) by cyclic voltammetry(CV). Inverted metallurgicalmicroscope was used to characterize the surface structure of Cu/Pt/n-n+-Si electrode andCu-CuO/Pt/n-n+-Si electrode. A two electrodes cell based on Cu-CuO/Pt/n-n+-Si electrode wasused as sensor for glucose photocurrent measurements at0.2V (vs Pt counter electrode) bychronoamperometry. The sensor shows good photocurrent response by adding differentconcentration of glucose with a good stability and reproducibility. The linear range for thedetection of glucose was2×10-5-2×10-4M, with a detection limit (S/N=3) of4.29μM. The newphotoelectrochemical sensor provides a reference for the research of non-enzymatic glucosesensor. The sensor shows general selectivity, which needs further to investigate.2.Glucose Molecularly Imprinted Electrochemical Sensor Based onChitosan(CS) and Nickel Oxide ElectrodIn this work, a molecularly imprinted polymers (MIPs) eletrochemical sensor based onchitosan and nickel electrode was constructed, finally used in glucose (Glu) measurement.Electrodeposition of NiO/Ni electrode in Glu-CS solution, at the applied voltage of-1.3V(vs.SCE) for300s, obtained the Glu-CS/NiO/Ni membrane electrode. Then, glucose wasremoved from the Glu-CS/NiO/Ni membrane electrode in0.2V KOH solution by cyclicvoltammetry, referring to Glu-CS/NiO/Ni MIPs electrode. The morphologies of NiO/Nielectrode, Glu-CS/NiO/Ni membrane electrode and Glu-CS/NiO/Ni MIPs electrode werecharacterized via scanning electron microscope (SEM), respectively. Three electrode cell basedon Glu-CS/NiO/Ni MIPs electrode was used as sensor for glucose measurements bychronoamperometry at the applied voltage of0.4V(vs SCE). The linear range for the detectionof glucose was1×10-5-1.9×10-4M, with a detection limit (S/N=3) of2.0μM, and the sensorshows good stability, reproducibility and selectivity. This new MIPs electrode provides areference to the research of non-enzymatic glucose sensor.