Characterization of Polymer-Grafted Nanorods by Depolarized Dynamic Light Scattering with Genetic Algorithm Optimization

Gold nanorods (AuNRs) have garnered significant attention due to their uniform dimensions and unique optical properties, making them promising candidates for various applications, including drug delivery, imaging, and sensing. For many of these applications, polymers are typically grafted to the AuNR surface to tune solubility, dispersion, immune response, and other important properties. However, characterizing polymer-grafted nanorods with electron microscopy can be difficult and time-consuming, while appropriate analytical form factors for neutron scattering analysis have yet to be identified. Here, we present a novel approach that combines depolarized dynamic light scattering (DDLS) with a genetic algorithm (GA) optimization method that uses the experimentally obtained relaxation rates to quickly determine the optimal dimensions of AuNRs, while also quantifying the deviation from theoretical values. Our work demonstrates that this approach is a fast, cost-effective, and versatile method for characterizing polymer-grafted nanorods in solution, thus addressing a critical need in nanomaterial characterization. Our study of polymer-grafted AuNRs not only aids in understanding polymer behavior but also opens up new possibilities for designing advanced nanocomposite materials.