▎ 摘　　要

Graphene based nanocomposites have successfully been employed for high yield and stable immobilization of oxidoreductive and hydrolytic enzymes. Enzymes immobilized both via adsorption and covalent attachment on graphene nanocomposites were found highly stable against various types of denaturants and were noticed less sensitive to inhibition mediated by their specific inhibitors. The oxidoreductases and hydrolases immobilized through graphene nanocomposites have resulted in the formation of robust biocatalysts which have easily been applied in various biosensors on their repeated uses. These nanocomposite bound enzymes have shown very high specificity, selectivity, broad ranges of linearity and sensitivity and very low detection limit. By using such types of techniques several enzymes have successfully been exploited. The results have demonstrated that in many cases the activity of enzymes was remarkably enhanced upon immobilization on such supports. Graphene mediated immobilized enzymes on electrodes have successfully been employed as biosensors for the analysis of various compounds in clinical, environmental, fuel and food samples. The compounds that have been detected by using such kinds of technology are acetylcholine, ethanol, H2O2, c, histamine, catechol, phenol, 4-CP, 3,4-DMP, 3-MP, 4-MP, 4-Cl-3-MP, 4,-Cl-2-MP, caffeic acid, 17b-estradiol, artesunate, CEA, H2S, BPA, captopril, glucose, urea, clenbuterol, Con A, OPs pesticides, paraoxon-ethyl and chlorpyrifos.