On-chip chemical fingerprinting of an analyte using both Raman spectroscopy and fluorescence

Optofluidics refers to the combination of optical techniques with LoC technology. The marriage of LoC technology with Raman spectroscopy has resulted in the development of an optfluidic technique called waveguide confined Raman spectroscopy (WCRS). The WCRS architecture is realized with a microfluidic chip within which one embedded optical fibers in such a way that maximum collection efficiency of Raman scattered photons was ensured while discarding the majority of the unwanted background signals from both the substrate of the microfluidic chip and the optical fibers. WCRS is a simple but powerful optofluidic architecture in which an embedded optical waveguide enables efficient delivery of the excitation beam and collection of Raman photons in a completely alignment-free manner. With embedded optical fibers, WCRS is completely alignment-free and can be considered as a straightforward 'plug-and-play' device for a benchtop or portable Raman spectroscopic system with a fiber-coupled laser and spectrometer.