A route to apply Ag nanoparticle array integrated with microfluidic for surface enhanced Raman scattering

Surface enhanced Raman spectroscopy (SERS) with enormous enhancements has shown great potential in single-molecule detection, however, the fabrication of large-scale and controllable substrates with high SERS activity is a major limitation. To achieve this goal, this paper provides method to fabricate wafer level SERS substrate with tunable nanoparticle sizes and interparticle gaps. The nanoparticle size, density, and shape are found to be dependent on the thickness of Ag film and the condition of annealing. Ag nanoparticles on the silicon substrate were packaged with polydimethylsiloxane (PDMS) microchannel before testing. The results of detections of Rhodamine 6G SERS spectra show that the fabrication protocol of such a SERS substrate is low-cost, easy-fabrication and inexpensive. Therefore, this substrate with Ag nanoparticle array may anticipate a wide range of applications in SERS-based sensors.