Fabrication of Mediator-Free Glutamate Sensors Based on Glutamate Oxidase Using Smart Micro-Devices

L-glutamate sensor based on glutamate oxidase (GLOx) has been fabricated on N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) activated thioglycolic acid (TGA) self-assembled monolayer (SAM) on smart bio-device using mediator-free simple phosphate buffer system (PBS), where TGA-SAM is used as an enzyme immobilization background. The glutamate sensor displayed a low detection limit (DL, 0.089 +/- 0.002 mu M), a wide linear dynamic range (LDR, 0.1 mu M to 10.0 mM), good linearity (R = 0.9931), and higher sensitivity (20.75 +/- 1.0 mu mM(-1) cm(-2)), small sample volume (70.0 mu l), as well as good stability and reproducibility. The smart-biodevice system exemplified a simple and efficient approach to the assimilation of GLOx and sensing surface, which can provide analytical access to a large group of enzymes for wide range of bio-electrochemical applications in health care fields.