Research Of The Ferrocene-tagged Peptide Nanomaterials Based Glucose Electrochemical Biosensors

Abstract:Glucose electrochemical biosensors get the widespread concern of the chemical workers for its characteristics (short response time, good stability and high sensitivity selective). However, it’s difficult for the electron to transfer to the surface of the electrode from the GOx active center, due to the redox active center of glucose oxidase (Glucose Oxidase, GOx) that surrounded by a layer of protein shell. To solve this problem, the electron mediator is used as a very effective means to enhance the efficiency of electron transfer between the enzyme active center and the electrode. Measuring the change in current value of the electron mediator can achieve the detection of the analyte.Ferrocene-Diphenylalanine (Fc-Phe-Phe-OH) can be self-assembly to nanowire (Fc-Peptide Nanowire, Fc-PNW), ferrocene-phenylalanine can be self-assembly to hydrogel (Fc-Phe-OH Hydrogel), both of them are the novel peptide nano-eletron-active substances via supramolecular self-assembly. In our article, we use Fc-PNW\Fc-Phe-OH hydrogel as a mediator that we also research the electrochemical properties of the materials and the new sensor constructed. The main contents are as follows:By using the Fc-PNW as the electronic mediator, we first prepared the Fc-Phe-Phe-OH, which can self-assemble into Fc-PNW. On the conditions of the presence of glutaraldehyde, the combined of chitosan (CS) and GOx can modified on the glassy carbon electrode (GC) to form a enzyme sensor, whose structure is CS/GOx/Fc-PNW/GC. In the experiment work, we have a study of the electrochemical performance of this sensor and the optimum conditions through the Amperometric i-t curve(i-t) and Cyclic Voltammetry (CV). The results show that:on the conditions of37℃and the phosphate buffer solution (PBS, pH=7.4), it’s more obvious of the glucose electro-catalysis. It’s better for the range of linear relationship between the concentration of glucose and the current value of FC-PNW catalytic oxidation peak is0.01～3mmolL-1and the detection limit is SOμmol·L-1. Moreover, the detecting to the blood glucose level of the blood sample is the same as the results obtained by the hospital.Via the Fc-Phe-OH hydrogel mediator, we first modified the glassy carbon electrode by the Fc-Phe-OH hydrogel prepared, by CS Fixed the glucose and the Fc-Phe-OH hydrogel composite to the surface of electrode can make the sensor of the CS/GOx/Fc-Phe-OH hydrogel/GC. In the research, we have studied the electrochemical properties of this sensor by scanning the CV and the optimum conditions for the glucose response. The data show that:the sensor response obviously in37℃, PBS(pH=7.4). This sensor has potential applications and the Fc-Phe-OH hydrogel may be used in other types of enzyme sensors.