Ag nanoparticles cladded with parylene for high-stability microfluidic surface-enhanced Raman scattering (SERS) biochemical sensing.

A method for fabricating the stable and reusable microfluidic-integrated devices based on the Ag nanoparticles cladded with parylene have been demonstrated, which can be applied for biochemical sensing. The excellent parylene cladding structure acted as a protection layer for the Ag nanoparticles, enhancing the Raman spectrum intensity by forming the hot spot structure between the nanoparticles. By optimizing the parylene film thickness, the surface enhanced Raman spectroscopy sensitivity of the R6G solution could be enhanced by three times, comparing with the initial substrate. The hydrophobic and biocompatible parylene cladding film also increased the repulsive to the molecular probes, enabling hundreds of measurement cycles and greatly increasing the stability and reproducibility. This method was also demonstrated to be reusable by flushing with water and alcohol through the integrated micro-channel. [ABSTRACT FROM AUTHOR]