Active nanomaterial-based platforms for biosensing applications

Anthropogenic activities provoke a growing spread of pathogens, which represent an increasing health and environmental threat. Rapid, simple, and on-site pathogen detection methods are urgently required as a sustainable alternative to mainstream diagnosis and environmental monitoring protocols. Our research activity develops nanoparticle-based platforms for efficient optical detection of pathogens in water and biological fluids. Plasmonic nanoparticles organized on suitable substrates (transparent, reflective or flexible) are then bioactivated to promote univocal interactions with a specific analyte, resulting in a sensitive and specific optical transducer. These interactions are detected by exploiting the phenomenon of Localized Surface Plasmon Resonance (LSPR), well identified by absorption spectroscopy. It results in a sensitive and specific optical transducer that associates the LSPR wavelength variation, namely a color change, with the detection and quantification of the analyte. We also develop and investigate colloidal metasurfaces by assembling plasmonic nanoparticles on a thin layer of a reflective material, in extremely precise way. Colloidal metasurfaces allow manipulating light in a way that is impossible by using natural materials, resulting in a biosensing platform with outstanding performance. In addition, the thermoplasmonic properties of the developed plasmonic platforms enable photo-thermal disinfection, thus allowing biosensor reusability.