In situ synthesis of directional gold nanoparticle arrays along ridge cracks of PDMS wrinkles

Abstract

The synthesis of gold nanoparticles (AuNPs) on polydimethylsiloxane (PDMS) substrates is generally influenced by the condition of the exposed PDMS surfaces. AuNPs are usually synthesized on native PDMS surfaces because it is difficult to do so on PDMS surfaces that have been treated by oxygen plasma. In this study, wrinkled PDMS substrates were generated by oxygen-plasma treatment under stretching and AuNPs were selectively formed on the ridge of the PDMS wrinkles by in situ reduction with gold chloride. To investigate the mechanism of the formation of AuNPs, the prepared wrinkled PDMS substrates were observed by liquid-mode atomic force microscopy. The synthesized AuNPs on the PDMS wrinkles were characterized using scanning electron microscopy. This study provides valuable insight into the synthesis of AuNPs on wrinkled PDMS surfaces, which can be applied to biosensors and optical devices.