Droplet formation via flow-through microdevices in Raman and surface enhanced Raman spectroscopy-concepts and applications

This review outlines concepts and applications of droplet formation via flow-through microdevices in Raman and surface enhanced Raman spectroscopy (SERS) as well as the advantages of the approach. Even though the droplet-based flow-through technique is utilized in various fields, the review focuses on implementing droplet-based fluidic systems in Raman and SERS as these highly specific detection methods are of major interest in the field of analytics. With the combination of Raman or SERS with droplet-based fluidics, it is expected to achieve novel opportunities for analytics. Besides the approach of using droplet-based microfluidic devices as a detection platform, the unique properties of flowthrough systems for the formation of droplets are capitalized to produce SERS active substrates and to accomplish uniform sample preparation. Within this contribution, previous reported applications on droplet-based flow-through Raman and SERS approaches and the additional benefit with regard to the importance in the field of analytics are considered.