Raman Spectroscopy of nanoparticles: substrates for ultra-sensitive detection and validation of a methodology for physical-chemical characterization of nanoplastics with analysis of physiological interactions in cell cultures

Abstract

The most immediate challenge of nanotechnology is the need to learn more about materials and their properties at the nanoscale, while one of the biggest problems that arise with the use of nanotechnology is the impact on the environment and toxicity to humans. In this project we present two goals that belong to different collaborations, which have in common the need to develop methodologies to detect and characterize nanoparticles (NPs), more specifically, nanoplastics (NPLs). The first goal, which is of a basic research nature, focuses on the development of highly sensitive sensors and a very low detection threshold for Raman scattering. The objective is to achieve an intensification of the Raman signal of hundreds of times, which will make the system comparable with the best SERS samples (Surface Enhanced Raman Scattering) that can be acquired commercially, without presenting the major disadvantages intrinsic to the SERS technique. The second goal with great social appeal, which belongs to applied research, deals with the validation of a methodology for the physicochemical characterization of NPLs. The environmental accumulation of micro and nanoparticles formed by material of anthropic origin has been raising doubts regarding their safety, mainly in the case of human body cells. However, due to the lack of adequate techniques, almost nothing is known about these NPLs with a diameter smaller than 3 mm. Therefore, new analytical techniques that can address chemical functionality and provide structural information at the same time with high spatial resolution are necessary. The present project aims to validate a methodology that will combine biochemical (cytotoxicity and quantification of oxidative radical formation), physiological (genotoxicity and microscopic analysis) and physical (Raman / TERS spectroscopy) assays for future evaluation of the possible effects that nanoplastics may cause on cells alive. (AU)