While centrifugation is possible irrespective of the presence of a protective and stabilizing shell around the C/S particles, prior PEGylation is preferred for AFFF. 𝛼-Carboxy-𝜔-mercapto PEG contains two terminal groups: a gold-seeking thiol group and a carboxyl group interacting with the solvent. PEGylation introduces a negative surface charge to the system and allows for the usage of negatively charged and commercially available PES membranes. In contrast, CTAB-functionalised C/S particles require positively charged membranes to avoid losses during the separation. However, the lack of commercially available positively charged membranes leads to avoidable challenges when separating non-PEGlyated C/S particles. Furthermore, the carboxy group facilitates further usage as immunolabels since free amino groups of antibodies can be conjugated to the carboxyl groups via an EDC/sNHS-linking strategy. Therefore, all AFFF experiments were exclusively conducted with PEGylated particles.