Carbon nanotube composite as novel platform for microbial biosensor

The presented work includes the development of a microbial biosensor based on a carbon-nanotube epoxy composite (CNTEC) platform used as supporting electrode for cell immobilization. For this purpose, cells of Pseudomonas fluorescens were immobilized on the surface of the CNTEC electrode by means of gelatin which was then cross linked with glutaraldehyde. After optimization of experimental parameters like cell amount, pH and temperature, the system was calibrated for glucose. From the calibration graph the linear range was estimated as 0.5 - 4.0 mM with a response time of 100 s. Furthermore, substrate specificity and operational stability were investigated. Finally, the results that were obtained with CNTEC electrodes were compared with conventional graphite epoxy composite electrode (GECE) and as a result, higher current values (2 to 3 folds) were observed with CNTEC microbial biosensor.