Sensitively fluorescent detection of H2 with resazurin hydrogenation reactions catalyzed by Pd/C nanocomposites

Developing a sensitive and reliable method for accurate determination of H 2 is of great importance for effective and safe utilization of H 2 in various conditions. A fluorescence (FL) assay for H 2 detection was proposed in the present work. It relied on the fact that Pd/C nanocomposites catalyzed fluorogenic conversion of weakly-FL resazurin (RZR) into highly-FL resorufin (RSR) was triggered by H 2 under ambient condition. This method possessed a limit of detection (LOD) as low as 0.06% volume concentration of H 2 in air, far below 4% that is the generally recognized as the lower explosion limit of H 2 -air mixture. A high selectivity to H 2 over O 2 , N 2 , Ar and CO 2 as well as broad linear response range from 0.2% to 80% made this method promising for H 2 sensing in a variety of circumstances. Most importantly, the developed method was able to detect practical H 2 atmosphere (2% H 2 in air) with high reliability under simple operation.