An H₂S-sensing/CO-releasing Flavonol that Operates via Logic Gates

Signaling molecules, including H₂S and CO, are involved in a complex interplay within cells to maintain cellular homeostasis. In order to investigate the intracellular interplay of different gasotransmitters, new molecular tools are needed that combine sensing and release capabilities of different small molecules in a single, multifunctional, and highly-regulated molecular platform. This report gives the first example of a combined H₂S sensor/CO-releasing molecule. This flavonol-based molecular tool operates intracellularly via a highly regulated AND logic gated input-output sequence and provides fluorescent feedback for the H₂S detection and CO release steps. This linear sequence can be combined with a fluorescent molecular sensor for CO detection via a third distinct emission. Overall, this is the first molecular framework that can combine the sensing of H₂S with the controlled release of CO, two gaseous molecules that are known to exhibit reciprocal regulation and have overlapping targets in cellular environments.