The main limitation, however, of virtually all polymers that are used to both manufacture LOC devices as well as to provide fluidic interconnects is their significant hydrophobicity. Conventionally the hydrophobic properties were postulated to impede wetting and priming of the polymeric chip-based devices and tubing interconnects. Such issues were often solved with plasma treatment or ethanol priming to help wet the polymeric substrata and also reduce the nucleation and persistence of air bubbles.
In this work, we present evidence that use of certain hydrophobic polymers is a significant impediment in performing ecotoxicity tests of organic chemicals on biomicrofluidic devices. We report on electrostatic interaction between polymers and toxicants that lead to non-covalent adsorption and rapid depletion of chemicals from the tested media. This introduces a significant bioanalytical bias irrespectively of the fact that microfluidic tests are preformed under continuous perfusion.