Exposing mesoporous ZrO 2 substrates with HGC-bound guests to the desorption conditions used for the gold (with heating of the solution instead of sonication, to preserve the mesoporous substrate), the removal of guests from the surface could be tracked by fluorescence spectroscopy. The same reversible desorption and re-adsorption of different guests (as was shown for the gold electrode using TERS) indicates that the surface can be modified without degrading the surface-bound hosts (Figure ).