Coordination Polymer as a Self-Calibrated pH and Amikacin Luminescence Probe

By the solvothermal assembly of Gd(NO 3 ) 3 ·6H 2 O, H 2 dht (H 2 dht = 2,5-dihydroxyterephthalic acid), and H 4 adip (H 4 adip = 5,5′-(anthracene-9,10-diyl)diisophthalic acid), a luminescent coordination polymer (CP) [Gd(adip) 1/2 (dht) 1/2 (NMP) 2 ] ( 1, NMP = N -methylpyrrolidone) has been prepared. 1 exhibits dual emission bands and has the fluorescence turn-on behavior toward pH and antibiotic amikacin (AMK). Therefore, 1 can serve as a luminescence turn-on self-calibrated sensing material to quantitatively detect pH value and AMK. In the pH range of 5.05–6.88, the sensitivity can reach 2296% per pH, which is the highest among all fluorescence pH sensors. 1 also shows excellent sensing properties for AMK, and a good linear relationship between the fluorescence intensity ratio and concentrations of AMK was observed with a slope of 1.2 × 10 5 M –1 . The limit of detection (LOD) is 7.7 × 10 –8 M. Meanwhile, 1 is also the first CP-based sensing material to detect AMK. In order to better understand the sensing phenomenon, we also discussed the sensing mechanism for pH and AMK in detail.