An Ultrasensitive Self‐Calibrating Terbium Metal Organic Framework for the Detection of Amphotericin B

ABSTRACT We successfully synthesized a 3D porous lanthanide metal–organic framework, [Tb (obdb)][Tb 1/3 (H 2 O) 7/3 ]·NMP ( Tb‐MOF ) with hydrated terbium ions in the pores by solvothermal method using 4′,4″′‐oxybis[1,1′‐biphenyl]‐3,5‐dicarboxylic acid (H 4 obdb) as ligand. It is worth mentioning that Tb‐MOF exhibits excellent performance in structural stability and fluorescence response. Even after soaking in various solvents and pH solutions for 3 months, Tb‐MOF can maintain its structural integrity and excellent stability. The fluorescence spectra show that Tb‐MOF not only exhibits the luminescence of the ligand centered at 368 nm ( I L ), but also emits the characteristic emissions of the metal terbium, among which the luminescence at 542 nm is the strongest. In the detection of antibiotic amphotericin B (AB), Tb‐MOF showed significant detection efficiency. Upon increasing the concentration of AB, the fluorescence intensity at 542 nm gradually decreased, whereas the fluorescence at 368 nm decreased rapidly. The I 542 / I L value showed a very high linear correlation with AB concentration, with the slope reaching 1.29 × 10 8 M −1 (0–100 μM). In the field of fluorescent sensors for AB detection, Tb‐MOF is notable not only for its impressively low LOD (limt of detection) of 0.072 nM but also for pioneering the application of a self‐calibrating ratio‐based detection method. To better elucidate this fluorescence sensing phenomenon, we also conducted a detailed discussion of the sensing mechanism for AB.