A photonic multifunctional moleculator powered by two-step energy transfer

Abstract

A multifunctional molecular logic system based on the differential fluorescence readouts at three wavelengths, 415, 480 and 550 nm, with singular excitation at 360 nm in the course of the two-step energy transfer cascade between three readily available standard fluorophores, coumarin 1 (Cou1), curcumin (Cur) and rhodamine 123 (Rh123) has been reported here, avoiding the multi-step synthetic reactions. The logic functionalities of all four single-input–single-output logic gates, all sixteen dual-input–single-output logic gates, a number of combinational logic gates (half-adder, half-subtractor, 2 : 1 multiplexer, 1 : 2 demultiplexer, 4-to-2 encoder and 2-to-4 decoder), and logically reversible Feynman and transfer gates have been executed on this molecular system. The logic outcome could be effortlessly switched through the whole array of all-photonic logic gates simply with the switching of chemical inputs and optical outputs under singular 360 nm excitation. The approach towards the multifunctional opto-chemical logic system is quite simple and it is a generalized method based model that should work well with other sets of fluorophores supporting multi-step excitation energy transfer. Versatile logic functioning and their effortless switchability on this molecular system would certainly contribute to the silico-mimetic molecular logic research as an alternative for putting together and interconnecting different gates to fabricate molecular integrated circuits (MICs).