Abstract: A method and a system for detection of presence or absence of analytes in fluids, the method comprising the steps of: a) contacting a fluid sample and a plurality of nanoparticles, the nanoparticles being functionalized with a selective ligand, the contact of the fluid sample with the nanoparticles being under conditions such that, the nanoparticles aggregate selectively on surface of their target analyte, forming a nanoparticle-analyte complex, the aggregation promoting the concentration of the nanoparticles on the surface of the target analyte; b) subjecting a fluid mixture of the fluid sample and the plurality of nanoparticles to SERS; c) measuring at least a SERS signal associated with the fluid mixture; d) spectrally analyzing the at least one SERS signal of step c); e) recognizing at least one defined SERS spectrum of the nanoparticle-analyte complex, through a SERS signal enhanced by the at least one narrow inter-nanoparticle gap.

Abstract: The universal one-pot and up-scalable synthesis of SERS encoded nanoparticles relies on the controlled co-absorption of mercaptoundecanoic acid (MUA) and the Raman code on the metallic surfaces of the nanoparticles. In contrast to most of the reported procedures which typically involve complex steps, the present method has demonstrated to be an easy and fast one-pot approach for the production of SERS-encoded nanoparticles. This versatile strategy allows for the SERS codification of particles with every molecule with affinity toward the metal surface, independently of its chemical nature, as exemplified here in the fabrication of 31 different encoded particles using the same standard procedure. In addition to the easiness of preparation, scalability to the liter regime, stability in aqueous solutions including PBS and chemical diversity, our SERS-encoded particles show considerably higher optical efficiency than those fabricated by using PEG or PVP polymers.

Abstract: A method and a system for detection of presence or absence of analytes in fluids, the method comprising the steps of: a) contacting a fluid sample and a plurality of nanoparticles, the nanoparticles being functionalized with a selective ligand, the contact of the fluid sample with the nanoparticles being under conditions such that, the nanoparticles aggregate selectively on surface of their target analyte, forming a nanoparticle-analyte complex, the aggregation promoting the concentration of the nanoparticles on the surface of the target analyte; b) subjecting a fluid mixture of the fluid sample and the plurality of nanoparticles to SERS; c) measuring at least a SERS signal associated with the fluid mixture; d) spectrally analysing the at least one SERS signal of step c); e) recognizing at least one defined SERS spectrum of the nanoparticle-analyte complex, through a SERS signal enhanced by the at least one narrow inter-nanoparticle gap.

Abstract: The universal one-pot and up-scalable synthesis of SERS encoded nanoparticles relies on the controlled co-absorption of mercaptoundecanoic acid (MUA) and the Raman code on the metallic surfaces of the nanoparticles. In contrast to most of the reported procedures which typically involve complex steps, the present method has demonstrated to be an easy and fast one-pot approach for the production of SERS-encoded nanoparticles. This versatile strategy allows for the SERS codification of particles with every molecule with affinity toward the metal surface, independently of its chemical nature, as exemplified here in the fabrication of 31 different encoded particles using the same standard procedure. In addition to the easiness of preparation, scalability to the liter regime, stability in aqueous solutions including PBS and chemical diversity, our SERS-encoded particles show considerably higher optical efficiency than those fabricated by using PEG or PVP polymers.