Figure 20.

Schematic representation of the self-amplifying chemical sensing process. The megagate selectively allows only the small analyte molecule (blue ball) to diffuse into the pore to actuate megagate. Upon the opening of the gate, the substrate (blue cubes) is able to access the enzyme to initiate a catalytic production of fluorescent molecules. Reprinted with permission from ⁶³, copyright (2013) J. Am. Chem. Soc.