Large-scale sensitivity adjustment for Gd-HMME room temperature phosphorescence oxygen sensing.

The oxygen sensing enhancement based on room temperature phosphorescence (RTP) of Gd-HMME adjusted by imidazole was studied. The phosphorescence intensity IP0 and the Stern-Volmer equations under different imidazole concentration were obtained, and the physical mechanism of imidazole regulating the oxygen quenching constant KSV was analyzed. It was found that the KSV value increased by ∼46 folds in the range of 12.4(1)-576.1(5) kPa-1, and the large-scale variation of KSV is conducive to the realization of high precision oxygen concentration measurement in a wide range. In addition, the standard deviation σ of continuous measurement results was given, and the limit of detection (LOD) was determined to be 6.6 ppm.