Fabrication and testing of a photonic ethanol biosensor

This paper introduces an optical based ethanol biosensor fabricated on polydimethylsiloxane (PDMS). The sensor consists of a detection chamber that includes fluid distribution channels, and micro-lenses with self-alignment structures for fiber optics positioning. The sensor design allows optical detection of ethanol concentrations based on co-immobilization of alcohol oxidase (AOX) and horseradish peroxidase (HRP) directly on PDMS under continuous flow conditions. For that, an immobilization process based on surface hydrophilization, salinization and enzymes co-immobilization was considered and tested. Experimental results showed that the sensor is able to detect ethanol concentrations up to 15 mM with a standard deviation of 0.97. Such results are very promising for the application in optical LOC systems used for online analysis.