Strategic Advancement in Inner Filter Effect Controllable Detection of Tetracyclines and Nitroaromatics in Real-World Matrices by Two-Dimensional Coordination Polymer

A new two-dimensional coordination polymer (2D CP) {[Cd(Br-BDC)₂(DABCO)₂(DMF)]·0.5DMF}_n (BrCP-1; Br–H₂BDC = 2-bromo-1,4-benzenedicarboxylic acid and DABCO = 1,4-diazabicyclo[2.2.2]octane) was synthesized via the solvothermal reaction. Interestingly, the BrCP-1 exhibits strong luminescent property in pure aqueous media as well as in the solid state over an extended period when excited at 320 nm, emitting at 425 and 458 nm. The high luminescent property was explored for the rapid detection of tetracycline antibiotics and nitroaromatic (NAC) explosives in real-world environmental samples, including milk, river water, and soil samples. The UV–vis and fluorescence spectroscopic studies were performed to explain the resonance energy transfer and inner filter effect sensing mechanism accurately. Besides, the correction intensity (I_corr) for each analyte and correct quenching efficiency (QE_corr) were also evaluated. The density functional theory (DFT) experiment was also performed to evaluate the theoretical energy profile of respective tetracycline antibiotics and NACs, which established a proper photoinduced electron transfer (PET) mechanism.