Ratiometric Fluorescence Detection of Mg 2+ Based on Regulating Crown-Ether Modified Annihilators for Triplet-Triplet Annihilation Upconversion.
Lin LiYilei DingChun ZhangHaiyu XianShuoran ChenGuoliang DaiXiao-Mei WangChangqing YePublished in: The journal of physical chemistry. B (2022)
Detection of magnesium ion has been of great significance considering its critical physiological activities. Herein, we report ratiometric fluorescence detection of Mg 2+ with high sensitivity and selectivity based on triplet-triplet annihilation (TTA) upconversion for the first time. Crown-ether functionalized anthracene derivatives were synthesized, which bifunctionally acted as not only annihilators to construct TTA upconversion systems but also the recognition probes for Mg 2+ based on the photoinduced electron transfer (PET) mechanism. Their photophysical properties with the absence and presence of Mg 2+ were comprehensively studied. It was found that solvents strongly influenced the photophysical properties and Mg 2+ -responsiveness. TTA upconversion systems with PtOEP as the sensitizer were further established and investigated. It turned out PtOEP/9-AEC in DCM exhibited an excellent linear relationship ( R 2 = 0.9979) between the intensity ratio (the integrated upconverted luminescence intensity ( I UC ) over the integrated downshifted phosphorescence intensity ( I PL ), I UC / I PL ) and the concentration of Mg 2+ under the excitation of 532 nm with a limit of detection value of 2.52 μM and a high selectivity to Mg 2+ . This work opened a new perspective of designs and applications of TTA-upconversion-based ratiometric fluorescence for ion detection.