Development of a glutamate biosensor based on glutamate oxidase using smart-biochips

Abstract

A highly sensitive L-glutamate biosensor 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-biochips, where K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Fe(CN) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> and TGA-SAM are used as a mediator and an enzyme immobilization matrix, respectively. The glutamate biosensor displayed a fast response, a low detection limit (DL, 0.072 muM), a wide linear dynamic range (LDR, 0.1 muM to 10.0 mM), good linearity (R=0.9843), and higher sensitivity (17.89 muAmM <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> ), small sample volume (70.0 mul), as well as good stability and reproducibility. The Au/TGA system exemplified a simple and efficient approach to the assimilation of GLOx and electrodes, which can provide analytical access to a large group of enzymes for wide range of bio-electrochemical applications in health care fields.