Nanosensing research line aims at developing novel multifunctional optical sensors enabling for smart applications in chemical and biological sensing through the molecular screening of samples with improved sensitivity towards selective analytes. Currently, the optical targeting of pathological biomarkers, highly diluted either in biofluids or in biopsies, represents the main topic of experimental work with great potential as diagnostic tools. To this end, the Nanosensing research is focused on the synergetic coupling of fiber-based spectroscopic techniques, mainly surface enhanced Raman spectroscopy (SERS), with (micro-) nano-structured platforms engineered to handle small volume of samples and to perform multiple analysis in parallel avoiding cross contamination. Polymeric devices are realized by combining traditional and advanced manufacturing techniques (e.g. laser-based 3D printing technologies) enabling for high design flexibility. SERS-active devices are then realized through selective immobilization of metal nanoparticles whose resonant and chemical properties can be tailored to achieve the highest signal enhancement from the target analytes. Particular attention is devoted to liquid biopsies analysis and analysis of fluids in general.