Parylene-coating in PDMS microfluidic channels prevents the absorption of fluorescent dyes

Absorption of fluorescent molecules is a troublesome property of microfluridic devices fabricated with PDMS The absorption raises background-levels of fluorescence from PDMS, and reduces concentrations of injected fluorescent molecules in PDMS channels We report here that conformal deposition of polyp-xylylene derivatives (parylenes) on the surface of PDMS substantially suppressed the absorption of Rhodamine B In a test of this technique, we found parylene-coated PDMS channels to be useful in accurate analyses using fluorescence intensity (C) 2010 Elsevier B V All rights reserved