As a new kind of analytical tool, biosensors which have the characteristics of good selectivity, high sensitivity, fast response, low cost and continuous on-line detection in complex system, have been widely applied in the clinical diagnosis, environmental monitoring, and food control etc. Because of the good physical, chemical, electrocatalytic and biocompatibility properties of nano-materials, applying nano-materials for the fabrication of biosensors will greatly improve the performance of the resulting b...