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

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2022-02, Vol.267, p.120490, Article 120490
• Main Authors: Zhang, Honglin, Liu, Ting, Li, Qiuhe, Zhang, Xiyu, Zhao, Hua, Zheng, Yangdong, Qin, Feng, Zhang, Zhiguo, Sheng, Tianqi, Tian, Ye
• Format: Article
• Language: English
• Subjects: Gd-HMME; Limit of detection; Phosphorescence; Quenching constant KSV
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2021.120490

[Display omitted] •The oxygen-sensitivity of KSV was improved by 46 times and the maximum value up to 576.1 kPa−1.•The Stern-Volmer equations kept high linearity at any imidazole concentration.•The mechanism of oxygen quenching constant KSV changes with imidazole was given.•The limit of detection (LOD) was 6.6 ppm with a well uncertainty of 3σ = 0.0038. 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.