Glucose microfluidic biosensors based on immobilizing glucose oxidase in poly(dimethylsiloxane) electrophoretic microchips

Here we reported a novel microfluidic biosensor with an on-column immobilized enzyme microreactor. The fabrication approach of this biosensor is simple and the enzyme microreactors with controlled sizes can be placed at any desired position on the microchip. Taking glucose oxidase (GOx) as an example, electroosmotic flow (EOF) as a driving force and amperometry as a detection method, the performance of biosensors were modulated by changing the length of enzyme reactor from 0.5 cm to 3 cm, and the linear ranges were changed from 0-8.0 mM to 0-30.0 mM with the detection limits from 42 μM to 6.5 μM. The enzyme reactor remained its 65% activity after 23 days storage. It also showed good anti-interference ability and was used to quantify glucose in human serum samples.