pH‐Responsive Supramolecular Nanovalves Based on Cucurbit[6]uril Pseudorotaxanes

An open and closed case: pH-controllable nanovalves that operate in water have been produced by attaching [2]pseudorotaxanes to the surface of mesoporous silica nanoparticles. The nanovalves are able to contain guest molecules (rhodamine B, red circles) within the nanopores at acidic and neutral pH values but release them on command when the pH value is raised (see picture).