A quinoline derivative-based supramolecular gel for fluorescence ‘turn-off’ detection of Fe3+ and Cu2+

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 Fe3+ and Cu2+, 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.