Mediator-less highly sensitive voltammetric detection of glutamate using glutamate dehydrogenase/vertically aligned CNTs grown on silicon substrate

► A highly sensitive glutamate biosensor is prepared based on glutamate dehydrogenase/vertically aligned carbon nanotubes. ► Vertically aligned carbon nanotubes were grown on a silicon substrate by direct current plasma enhanced chemical vapor deposition method. ► Characterization of the prepared biosensors is performed by the means of SEM, cyclic voltammetry and electrochemical impedance spectroscopic techniques. ► Nanomolar detection limits together with a wide range of the linear calibration curve of the concentration vs. peak current is obtained for glutamate.