A portable surface-enhanced Raman spectroscopy platform for biofluid analysis

Portable Raman and surface-enhanced Raman scattering spectroscopy (SERS) systems have gained great interest in biomedical science, especially when combined with microfluidics, since it allows the application of this sensitive technology in low-resource settings, providing fast results at a low-cost level. Moreover, these portable systems are also more versatile and user-friendly than microscope-based approaches. In this work, we propose the design of a complete portable SERS equipment for the analysis of biofluids. The system was optimized and tested using the Raman reporter 4- mercaptobenzoic acid (4-MBA) and, as a proof of concept, we performed a calibration curve using another Raman reporter: 1-naphtalenethiol (1NAT), being able to detect concentrations as lower as 2*10^-4 M. The results presented here show the potential of the system to detect different and relevant biomarkers, and even be part of more complex systems like Point-of-care or Lab-on-a-chip devices.