Evaluation of substituted-1,10-phenanthroline complexes of osmium as mediator for glucose oxidase of Aspergillus Niger

A series of novel substituted-1,10-phenanthroline complexes of osmium and r uthenium have been synthesized and characterized electrochemically with res pect to their ability to act as electron transfer mediator for glucose oxid ase. These complexes exhibit high second-order rate constants for reduced g lucose oxidase in the order of 10(6)-10(7) M-1 s(-1). The complexes bearing electron-donating substituents give a significantly higher rate constant w ith glucose oxidase and lower redox potential than those bearing electron-a ccepting substituents. 4,7-Dimethy-1, 10-phenanthroline and 3,4,7,8-tetrame thy-1,10-phenanthroline complexes of osmium have been characterized in deta ils as mediator for glucose oxidase. The application of the family of media tors in amperometric biosensors seems feasible. (C) 2000 Elsevier Science B .V. All rights reserved.