Fabrication of L-Lactate Biosensor Based on Redox Species Mediated Lactate Oxidase Using Micro-device

Abstract

A sensitive L-lactate biosensor based on redox species (K3Fe(CN)6) mediated lactate oxidase (LOx) has been fabricated on N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC) activated Thioglycolic acid (TGA) self-assembled monolayer (SAM) on micro-device, where K3Fe(CN)6 and TGA-SAM are used as a mediator and an enzyme immobilization matrix, respectively. The lactate biosensor displayed a low detection limit (DL, 0.299 nM), a wide linear dynamic range (LDR, 0.1 nM to 1.0 mM), good linearity (R=0.9887), and higher sensitivity (0.1242 μAμM-1cm-2), and small sample volume (70.0 μl) as well as good stability and reproducibility. The Au/TGA system exemplified a simple and effective approach to the assimilation of LOx and electrodes, which can provide analytical access to a large group of enzymes for wide range of bio-medical applications in health care fields.