There is a great need for functional coatings that support the interaction between living matter and devices; for example sensors and implants. In my research, I design and build such interfaces, often by the use of gold nanoparticles. These particles are larger than most molecules, but similar in size to proteins, making them ideal for engineering and detection at the single protein level. Furthermore, gold nanoparticles provide a great contrast in many imaging techniques. In the present project I design interfaces, functional nanoparticles and methods that can be used for separation and imaging of proteins in artificial cell membranes.