A quinoline derivative-based supramolecular gel for fluorescence 'turn-off' detection of Fe 3+ and Cu 2 .

In this research, we synthesized and constructed a novel gelator (named QN ) combining quinoline and naphthalene that self-assembled in N, N-dimethylformamide (DMF) to form a stable supramolecular gel (named OQN ). Under UV light, gel OQN exhibited extremely bright yellow fluorescence. The gel OQN showed excellent sensing performance for both Fe 3+ and Cu 2+ , with a fluorescence 'turn-off' detection mechanism and the lowest detection limit of 7.58 × 10 -8 M and 1.51 × 10 -8 M, respectively. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectra, x-ray powder diffraction (XRD), rheological measurements, x-ray photoelectron spectroscopy (XPS), and fluorescence spectroscopy were used to characterize the gel OQN . The OQN ion-responsive membrane created is an excellent fluorescent writing material.