Highly sensitive bifunctional sensor of a dinuclear terbium complex

Abstract A new dinuclear terbium complex (Tb-complex) is designed and synthesized based on 2,4,5-Trifluoro-3-methoxybenzoic acid (HTFMBA). The exact structure of the Tb-complex is determined to be [Tb 2 (TFMBA) 6 (phen) 2 ] (phen = phenanthroline). It crystallizes in the triclinic space group P -1, and it is further characterized by FT-IR, PXRD, EA, TGA and luminescence. Tb-complex shows very high luminescence quantum yield (QY) of 61.5%. Detailed investigation reveals that the Tb-complex is a highly sensitive and selective bifunctional sensor for detecting S O 4 2 − and CH 3 Hg + . Responsive behavior shows the detection has excellent linear relationship between luminescence and the concentration of S O 4 2 − and CH 3 Hg + . The limit of detection (LOD) for detecting S O 4 2 − and CH 3 Hg + are as low as 5 × 10 −7  M and 2.8 × 10 −9  M, respectively. This is the first bifunctional sensor that could probe the highly toxic CH 3 Hg + , and it is the most sensitive chemosensor for detecting CH 3 Hg + . Further investigation also reveal that the Tb-complex is applicable in sensing S O 4 2 − and highly toxic CH 3 Hg + in real water samples.