A rhodamine embedded bio-compatible smart molecule mimicking a combinatorial logic circuit and ‘key-pad lock’ memory device for defending against information risk

Abstract

Organic molecules with the possibility of logic operations are highly useful building blocks for the development of molecule-based “intelligent” devices for information processing applications. We have designed herein a very simple bio-friendly chemosensor (L^C) equipped with a rhodamine fluorophore moiety. This probe showed a chromo-fluorescence response profile for Al³⁺ but a colorimetric response for Cu²⁺ metal. The absorption responses of L^C caused by these metal ions along with the “OFF–ON–OFF” fluorescence behavior of an L^C–Al³⁺ complex towards EDTA were employed for the development of a three-input and one output combinatorial molecular system. Interactions of the mentioned metal ions with L^C in controlled sequential experiments gave fluorescence responses, enabling us to fabricate a ‘key-pad-logic’ function. So, a single molecular system performing such multiple ‘Boolean’ operations not only simplifies the complexity of a chemical driven ‘Intelligence’ device but also enriches the security of such a device against information invasion due to the sequence controlled sensor–analyte interactions and may find potential applications in biocompatible molecular logic platforms.