Off-on-off fluorescent chemosensor for pH measurement with a terbium(iii) complex based on a tripodal salicylic-acid derivative.
New Tb(iii) and Eu(iii) complexes have been synthesized as potential pH probes using a tripodal substituted-salicylic ligand (H3). Among them, this carboxylate ligand is found to be a good sensitizer for Tb(iii) emission owing to the superior match of the triplet energy level of the ligand with the (5)D4 emitting level of Tb(iii). The resulting · complex exhibited high sensitivity in the physiological pH range with significant "off-on-off" fluorescence changes in aqueous solution. Furthermore, this unique rare-earth complex has been successfully used to monitor pH variations within HeLa cells and with filter papers.
State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China. pengyu@lzu.edu.cn.
Yan-Ling
YL
Yang
Ya-Wen
YW
Wang
Dong-Zhu
DZ
Duan
Ai-Jiang
AJ
Zhang
Jian-Guo
JG
Fang
Yu
Y
Peng
D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D020156:Salicylic Acid / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013725:Terbium / Q000737:chemistry*
D005456:Fluorescent Dyes; D009942:Organometallic Compounds; D013725:Terbium; D020156:Salicylic Acid