A label-free solution-phase sensor for protein binding on membrane surfaces based on localized surface plasmon resonance from a suspension of membrane-coated colloidal silver nanocubes. An ultra-thin silica shell coated on silver nanocubes enables formation of a fluid supported membrane. Solutions of free-standing nanocube sensors can be made to support an arbitrary and wide range of membrane/protein compositions just by mixing them with the appropriate membrane vesicles and then read out using a standard laboratory UV-Vis spectrophotometer.

https://www.nature.com/articles/nmeth.2211

https://link.springer.com/protocol/10.1007/978-1-0716-2148-6_4