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 I P0 and the Stern-Volmer equations under different imidazole concentration were obtained, and the physical mechanism of imidazole regulating the oxygen quenching constant K SV was analyzed. It was found that the K SV value increased by ∼46 folds in the range of 12.4(1)–576.1(5) kPa −1 , and the large-scale variation of K SV 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.