Optical-switched proton logic gate: Indocyanine green decorated HSB-W5 MOFs nanosheets

Proton conduction controlled by light is important for advanced applications in sensors and information processing devices. We herein report a metal-organic framework (MOF) thin film by introducing indocyanine green dye into HSB-W5 (HSB = hydrogenated Schiff base) matrix (ICG@HSB-W5) to construct a series of basic logic gates (NOT, NAND, and NOR) on account of its good photothermal conversion ability and photo-controlled proton conductivity. The proton conductivity of ICG@HSB-W5 thin film is 25 times higher than that of the pristine HSB-W5 thin film and responses efficiently to lasers. In addition, the change of proton conductivity is very large with an ON/OFF ratio above 1000 and enough to be distinguished to build logic gates. In this logic gate system, 808- and 405-nm lasers are used as inputs and the proton conductivity is used as output signal with different thresholds. The electrical output signal is convenient and available to be received and detected. It offers a new route for the design of molecular logic gates based on MOF and facilitates the construction of proton-based logic gate or more complicated logic devices.