Biocompatible surfaces: Cationic, anionic, and neutral nanoparticles (NPs) were immobilized via dithiocarbamate formation onto polyethylenimine (PEI) films to create biofouling resistant surfaces. These surfaces are designed to bind proteins without denaturation, hence preventing biofouling. Extended incubation of these surfaces with BSA and serum demonstrate minimal fouling, providing a new methodology for generating surfaces resistant towards protein fouling.