Preparation Of Nitrogen-doped Graphene And Detection Of Biological Molecules

With the progress of science and technology, graphene gradually became the rising star of carbon nanomaterial after the discoveries of fullerenes and carbonnanotube. Particularly, graphene(GR) have widely used in the preparation of sensors and biosensors due to their large surface area, extraordinary electronic transport property, high electrocatalytic activity, good mechanical strength, high thermal conductivity and high mobility of charge arriers. As for the modified electronic structure of graphene has become a hot topic in the last two years. By changing the electronic band structure of graphene, we could make graphene electrical properties change, and doping has become to the most direct means of changed graphene electronic structure and increase the conductive propertiest. After studying chemical doping method of the nitrogen-doped graphene, we successfully prepared the 1, 3, 6, 8-pyrene tetra sulfonic acid sodium salt functionalized nitrogen-doped graphene electrochemical sensors, and research the electrochemical behavior of Simultaneous determination of uric acid, xanthine and hypoxanthine, the specific contents are as follows:(1) Preparation of functionalized nitrogen-doped grapheme: firstly, the graphene oxide we prepared by the improved Hummers’ method. Then the mixed used of thermal annealing method for the synthesis of nitrogen doped graphene andvmelamine. The nitrogen-doped grapheme was functionalized by pyrene tetra sulfonic acid sodium salt used the ultrasonic method, after functionalized the nitrogen-doped grapheme, the Water solubility and conductive greatly enhanced.(2) Electrochemical detection of biological molecules: We simultaneous determination the electrochemical behavior of uric acid, xanthine and hypoxanthine by the functionalized nitrogen-doped graphene electrode. The results showed that under the condition of p H=7.9, the linear range for the determination of uric acid, xanthine and hypoxanthine were 9-1000, 8-800 and 8-200μM, with the detection limits(S/N=3) of 0.331, 0.0838 and 0.231μM, respectively. The proposed method was further applied to content in real sample analysis, human serum and urine samples were selected as real samples for analysis, and the recovery was in the range of 97.2–101.0 %.