Strategy of\nConstructing Ratio-Dependent Coordination\nPolymer probes and Their Film Application with a Smart Phone for Detection\nof Lomefloxacin Hydrochloride and Sodium Salicylate

Lomefloxacin hydrochloride (LMFX) and sodium salicylate\n(SS) are\nimportant targets for real-time detection due to their widespread\nuses in daily life; accurate and portable monitoring of LMFX and SS\nis crucial for human health concerns accordingly. Developing a precise\nand smart platform for determination of the above analytes remains\na significant challenge. Herein, a high-sensitivity platform incorporating\na luminescence electrospinning film, self-designed smart-phone app,\nand portable 3D printing device has been developed to identify LMFX\nand SS. In this work, two heterometallic coordination polymers with\ntwo-dimensional layer structures have been synthesized based on 2,2′-oxidiacetic\nacid ligand (H<sub>2</sub>oda), namely, [LnPb(oda)<sub>2</sub>(CH<sub>3</sub>COO)]<sub><i>n</i></sub> [Ln = Eu (<b>IMU-1</b>); Tb (<b>IMU-2</b>)]. <b>IMU-1</b> and <b>IMU-2</b> were ratio-dependent luminescence probes, which could selectively\nand sensitively sense with LMFX and SS, respectively. Additionally,\nthe synthesized electrospinning films incorporating <b>IMU-1</b> and <b>IMU-2</b> were employed to identify LMFX and SS. Both\nfilms could rapidly photograph and color-capture through a portable\n3D printing device, along with a self-designed smart-phone app that\nenabled convenient and quick determination of the concentrations of\nthe above analytes. Remarkably, the mechanism exploration indicated\nthat electron transfer from ligands to analytes affected the antenna\neffect and further utilized the intrinsic luminescence of analytes\nalong with the luminescence quenching of Ln<sup>3+</sup> ions. Furthermore,\na strategy for constructing ratio-based fluorescent probes by exploiting\nthe luminescence of analytes and Ln<sup>3+</sup> ions in host coordination\npolymers is proposed. This work provides a new insight by combining\nluminescence probes, portable devices, and a smart-phone app for real-time\ndetection of drugs and food additives.