Novel reagentless glucose biosensor based on ferrocene cored asymmetric PAMAM dendrimers

A novel amperometric glucose biosensor is fabricated with immobilization of glucose oxidase (GOx) onto PAMAM-Fc dendrimers decorated gold electrode. Series of asymmetric PAMAM dendrimers containing a single ferrocene unit located in the focal point of these macromolecules have been synthesized and characterized. Surface of the gold electrode was covalently modified with 3-mercaptopropionic acid, PAMAM-Fc dendrimers and GOx enzyme by using coupling agents, respectively. The PAMAM-Fc/GOx biosensor shows an excellent performance for glucose at +0.25 V with a high sensitivity (6.54 μA/mM) and lower response time (∼3 s) in a wide concentration range of 1-22 mM (correlation coefficient of 0.9988). In addition, PAMAM-Fc/GOx biosensor possesses better reproducibility, storage stability and there is negligible interference from other electroactive components.