Poly(dimethylsiloxane) (PDMS) is widely used as a microfluidics platform material; however, it absorbs various molecules, perturbing specific chemical concentrations in microfluidic channels. We present a simple solution to prevent adsorption into a PDMS microfluidic device. We used a vapor-phase-deposited nanoadhesive layer to seal PDMS microfluidic channels. Absorption of fluorescent molecules into PDMS was efficiently prevented in the nanolayer-treated PDMS device. Importantly, when cultured in a nanolayer-treated PDMS device, yeast cells exhibited the expected concentration-dependent response to a mating pheromone, including mating-specific morphological and gene expression changes, while yeast cultured in an untreated PDMS device did not properly respond to the pheromone. Our method greatly expands microfluidic applications that require precise control of molecule concentrations.
METHOD SUMMARY A PDMS microfluidic device was bonded using a nanoadhesive layer deposited via initiated chemical vapor deposition (iCVD). The barrier property of the nanoadhesive was tested by measuring the absorption of fluorescent dye into PDMS. The yeast response to pheromone was tested in a PDMS microfluidic device sealed with nanoadhesive and compared with the response in an untreated PDMS device.