Direct Integration of Surface Enhanced Raman Spectroscopy as a Detection Mode for Microfluidic Separations and Fluid Handling: μfluidic-SERS

The arena of microfluidics (µfluidics) has grown over the past decade to encompass myriad separation techniques and exploit copious detection modes. The direct integration of a vibrational spectroscopic detection technique, rich with structural information, onto a platform that is portable and potentially highly controllable such as µfluidics, could offer redress for some of the problems inherent in many of the electrophoretically driven separations carried out on said devices. Herein, this direct integration is explored, and methods of device fabrication, spectroscopic data collection conditions, analytical figures of merit of the detection technique, and separations method development results are discussed. The creation of surface enhanced Raman scattering/spectroscopy (SERS) substrates within the architecture of miniaturized separation devices made of glass, polymer, silicon, and combinations thereof represents not only a novel and useful detection tool for µfluidics but also a facile means of interrogating new, optimized SERS substrates for increased enhancement activity with low-volume fluidic delivery. Finally, the contemporary, “real-world” relevance of the development of µfluidic-SERS comes to light with preliminary studies of aflatoxins, a fungal byproduct contaminating foodstuffs and a threat from both an agribusiness and a Homeland Security standpoint, and, even more important, endocrine disrupting chemicals, a wide class of ubiquitous pollutants that act both as acute teratogens and, in the long term, as potent carcinogens.