A semiconductor and fluorescence dual-mode room-temperature ammonia sensor achieved by decorating hydroquinone into a metal–organic framework

Presented herein is a magnesium-organic framework (SNNU-88) incorporated with active hydroquinone groups, which exhibits not only remarkable semiconductor sensing for traces of ammonia vapor (5-100 ppm), but also extra-high fluorescence response to liquid NH3·H2O through an unusual turn-off (0-1.5 ppm) and turn-on (3.0-100 ppm) luminescence sensing mechanism at room temperature. Such bifunctional quantitative ammonia detection together with the extraordinary sensitivity and selectivity, fast response, and good reusability makes SNNU-88 one of the most powerful ammonia sensors.