PDMS bonding to organically-modified solid surface using photocatalyst for fabricating low-cost plastic microchip

A novel PDMS bonding technique using photocatalyst has been developed to fabricate polymer-based DNA sample preparation microchip for molecular diagnostics. To bond PDMS substrate onto organosilane-modified pillar arrays, organosilane layer on top plane of micropillars was selectively removed through photocatalytic oxidation using TiO₂ and UV irradiation. The proposed method exposed underlying SiO₂ surface without deteriorating the organic film on lateral surface of the micropillars which is used for bacterial adhesion, and then resulting SiO₂ layer was bonded to PDMS. The low-cost plastic DNA sample preparation chip has been successfully fabricated and it demonstrated similar performance to Glass/Si chip in terms of bacterial cell capture efficiency and PCR compatibility.