Magneto-plasmonic nanoparticles for optical sensing of contaminants of emerging concern

Magneto-plasmonic nanoparticles are hybrid materials that combine features from ferromagnetic and noble metals. These types of nanoparticles exhibit outstanding optical properties of noble metals and the magnetic behavior of ferromagnetic materials. Due to their unique properties, in recent years the study of this type of nanoparticles is at the forefront of many nanotechnology applications such as catalysis, bio-separation, and chemical sensing. This work is focused on the development of an optical technique based on a total internal reflection configuration with the use of colloidal core-shell nanoparticles for the sensing of organic pollutants in freshwater. Specifically, gold-coated magnetite nanoparticles (Fe₃O₄@Au) will be studied due to the localized surface plasmon resonance (LSPR) of these nanoparticles that can be fine-tuned over a wide spectral domain. In addition, these particles exhibit magnetic properties that allow the facile manipulation of the nanoparticles in the presence of a permanent magnet. Simultaneously, the gold shell of these nanoparticles is optically active, which will enable analyte detection via fluctuations of the reflectance curve which occur when molecules bind to the gold surface. Computational as well as experimental work will be developed to synthesize and characterize the sensor capabilities.