Networked Multicomponent Ensemble as AND Gate with FRET Output

A networked supramolecular logic AND gate system is accomplished using precise chemical communication within a multicomponent ensemble via metal ion-driven self-sorting processes. The cybernetic AND gate is composed of a copper(I)-loaded nanoswitch, an aza-crown ether and a rhodamine receptor. The modus operandi of the AND gate, from state (0,0), was induced with stoichiometric amounts of two inputs (IN-1=Hg²⁺, IN-2=Li⁺) generating copper(I) ions as output only in state (1,1). Generation of state (1,1) from state (0,0) involves selective Cu⁺ ion translocation from the nanoswitch to the aza-crown ether in the first step (IN-1) and then from the aza-crown ether to the rhodamine receptor in the second step (IN-2). The released copper(I) output acts as a messenger that binds to the rhodamine receptor, triggering it's spiro-lactam ring opening, which leads to a diagnostic FRET emission from the copper(I)-loaded rhodamine scaffold accompanied by a remarkable fluorescence and colour change from pale yellow to pink.