Zr-MOF Nanoparticles Crafted from Conjugated Imidazolyl Carboxylic Acid Ligands for Sensitive Fluorescence Detection
Fangfang Chen1, Xiudu Zhang1, Wensen Du1
1College of Chemistry and Materials Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Normal University, Wuhu 241002, China.
Abstract:
2,4-Dinitrophenol (2,4-DNP) and p-nitroaniline (PNA), as hazardous nitroaromatic explosives and persistent organic pollutants, exhibit high toxicity, nonbiodegradability, and carcinogenicity. Exposure to these compounds can cause severe health issues, including cardiovascular, neurological, and renal damage. In this study, a novel zirconium-based metal-organic framework (Zr-MOF, denoted as Zr-BPBI) was synthesized via a solvothermal reaction using the ligand 4,4',4″,4‴-([1,1'-biphenyl]-4,4'-diyldi(1H-imidazole-2,4,5-triyl))tetrabenzoic acid (H4BPBI) and ZrCl4. The investigations showed that the original synthetic parameters, including surfactant concentration, acid type, reaction time, and temperature, could strongly affect the morphology, particle size, and fluorescence performance of the as-prepared Zr-BPBI. Interestingly, under excitation at 422 nm, the as-prepared Zr-BPBI nanoparticles (Zr-BPBI-NP) emitted blue luminescence centered at 502 nm, which demonstrated exceptional sensitivity toward PNA and 2,4-DNP with rapid fluorescence quenching responses (within 30 s for 2,4-DNP and 15 s for PNA). Simultaneously, common interfering substances (e.g., small molecules and ions) did not affect the above detection, suggesting high selectivity of the as-prepared Zr-BPBI-NP fluorescent probe. The corresponding limits of detection were 0.36 μM for 2,4-DNP and 0.4 μM for PNA. Obviously, the present Zr-BPBI-NP fluorescent probe is a new option for the highly sensitive and selective detection of PNA and 2,4-DNP in actual aqueous environments.
