Poly(dimethylsiloxane) surface modification by plasma treatment for DNA hybridization applications

Abstract

In this work, the surface modification of poly(dimethylsiloxane) (PDMS) was carried out by using a 2-step plasma modification with Ar followed by acrylic acid (AAc). The optimal conditions were found to be 0.5 mm with Ar at 0.7 mbar; and 5 mm with AAc at 0.2 mbar. The water contact angle (WCA) of the native PDMS decreased from 110° to 30 after modification, then stabilized to values between 50° to 600 after 1 day exposure to air. The stability of the modified PDMS was further improved by Soxhlet-extracting the PDMS with hexane prior to plasma treatment. Atomic force microscopy (AFM) showed significant changes in surface morphology after the 2-step plasma modification. X-ray photoelectron (XP..