not-yet-known not-yet-known not-yet-known unknown Phase Transfer: The aqueous FVIOs suspension was prepared by coating DHCA on the surface of nanorings via a ligand exchange of oleic acid. Oleic acid-coated FVIOs (10 mg) and DHCA (500 mg) were dispersed in a THF solution in a three-neck flask, which was stirred at 65 °C for 5 hours under Ar flow. The DHCA-modified FVIOs (DHCA-FVIOs) were washed and centrifuged with deionized water and stored in phosphate buffered saline (PBS, 0.1 M, pH 7.4) for further experiments.