A simple low-cost method to enhance luminescence and fluorescence signals in PDMS-based microfluidic devices

We present a simple and low-cost method to increase the signal intensity originating from poly(dimethyl)siloxane (PDMS) based microfluidic devices by modifying the optical properties of the polymer. The addition of titanium dioxide results in an opaque, white composite with enhanced light reflection properties. The composite can be used to increase the collected light from fluorescent and luminescent moieties inside microfluidic channels by up to 11-fold, as well as reducing the background signal in luminescence studies. Both of these effects increase sensitivity and lower detection limits in analytical setups based on PDMS microfluidic devices. Furthermore, the production of the composite material is simple, low-cost and can be implemented in standard PDMS device fabrication.