Manufactured using proprietary methods that result in exact sizes, highly monodisperse sizes and shapes, along with significantly improved reactivity. Diameters from 1. 8nm to 125nm with size accuracies up to 0. 1nm and size variances less than 4% at sizes larger than 40nm. Peak SPRs range from 505nm to 570nm. Every batch is completely characterized including size, monodispersity, aggregation, residual chemicals, and concentration. A Certificate of Analysis (COA) is provided exhibiting TEM and UV-VIS images and data, as well as DLS data.