A novel glutamine biosensor based on zinc oxide nanorod and glutaminase enzyme from Hypocria jecorina.

A novel biosensor for determination of L-glutamine in pharmaceutical glutamine powder was developed via immobilizing our produced glutaminase enzyme from Hypocria jecorina onto our prepared zinc oxide (ZnO) nanorod and chitosan. ZnO nanorods were prepared as surface-dependent and surface-independent and both were used. The biosensor is specific for L-glutamine and the peculiar analytical properties (linearity range, reproducibility, and accuracy) of it were experimentally determined. The optimum operating conditions of the biosensor such as buffer concentration, buffer pH, and medium temperature effect on the response of biosensor were studied. Km and Vmax values for the our-producing glutaminase enzyme from Hypocria jecorina immobilized on the biosensor were also determined as 0.29 mM and 208.33 mV/min., respectively, from Lineweaver-Burk plot. The biosensor was then used for the determination of glutamine contained in pharmaceutical formulations.