*2.2. Dynamic Light Scattering and Zeta Protocol*

For dynamic light scattering (DLS), the hydrodynamic diameters of the nanostars under investigation were measured using a Zetasizer Nano ZS90 DLS system equipped with a red (633 nm) laser and an Avalanche photodiode detector (APD) (quantum efficiency > 50% at 633 nm) (Malvern Instruments Ltd., Malvern, UK). Hydrodynamic diameters represent estimates of average diameters as the Zetasizer Nano ZS90 DLS system is optimized for spherical nanoparticles and not nanostars. A 1.5 mL semi-micro cuvette was used as sample container. The 'DTS applications 5.10 software was used to analyze the data. All sizes reported here were based on intensity average where the intensity was observed using a non-negative least squares (NNLS) analysis method. For each sample, two DLS measurements were conducted with a fixed 15 runs and each run lasts 10 s. A detection angle of 173◦ was chosen for the size measurement.

For determining the zeta potential, an average was taken on three distinct measurements where the nanostars were dissolved in water. A u-shaped polycarbonate flow cell with embedded electrodes at either end, referred to as 'clear disposable zeta cell', was used during these measurements. As with the size experiments the 'DTS applications 5.10software was used to process the data.
