Quantitation of Nanoparticle Composition Using Thermogravimetric Analysis

Some nanoparticles, such as metallic nanoparticles, often include a surface coating or surface modification to aid in its dispersion and stability. As this surface coating may affect the behavior of nanoparticles in a biological environment, it is important to measure. Thermogravimetric analysis (TGA) can be used to determine the amount of surface coating, approximate sample component proportions, decomposition temperatures, and/or nanoparticle residues. TGA is an experimental technique to measure the change in mass of a sample as a function of temperature and/or time in a controlled atmosphere (1). TGA experiments run under inert atmosphere can also be used to determine residual metal content present in the sample.This protocol describes the use of the TGA for a variety of nanoparticle samples, including sample preparation, data analysis, and experimental considerations. Specifically, the protocol examines the TGA analysis of polyvinylpyrrolidone (40 kDa PVP) stabilized silver nanoparticlesas a detailed example of coating quantification, in addition to other examples of nanoparticles analyzed in our lab. A detailed protocol for the analysis of organic coatings on metallic nanoparticles is published in reference (2).