Abstract: UVradiation was applied to modify the surface of poly(dimethylsiloxane)(PDMS) fabricated microfluidic replica. After the surface of PDMSwas irradiated by a 6 Wlow pressure mercury lamp, the adhesion between PDMSplates was significantly strengthened, and the PDMSplates were irreversibly sealed when the irradiated surfaces were brought into contact. Hydrophilic behavior of PDMSreplica was improved due to the photochemical reaction induced by UVradiation, resulting in a significant increase in the electroosmotic flow of buffers filled in the microchannels of the chip. Compared with the reported procedures using oxygen plasma pretreatment, the present approach allows one to easily modify the surface of PDMSplates using very simple and cheap equipment available in analytical laboratory.

Key words: Microfluidic analytical system, PDMS chip, Photochemical surface modification