Synthesis of corn bract cellulose-based Au³⁺ fluorescent probe and its application in composite membranes

To achieve real-time monitoring of Au³⁺, a corn bract cellulose-based fluorescent probe MAC-1 for was synthesized. MAC-1 showed good fluorescence properties in DMF-H₂O (1:9, v/v, pH = 7.4) solution, showed a fluorescence emission peak at 520 nm with quenching fluorescence properties for Au³⁺. The structure of MAC-1 was analyzed by SEM (Sample microstructure images), XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), ¹H NMR, Elemental analysis, EDS, Mapping and TG (Thermogravimetry) were analyzed. The fluorescence properties of the probe were also characterized by UV spectrophotometer and fluorescence spectrophotometer. The results showed that the recognition of Au³⁺ by the probe MAC-1 exhibited high selectivity and high sensitivity. Moreover, it is highly resistant to interference and has a short response time, which can be rapidly responded within 1 min. In addition, to improve the practical application of the probe, the probe was prepared as a fluorescent composite film and the fluorescence effect shown by the fluorescent composite film is consistent with the fluorescence change of the probe MAC-1 itself. The fluorescent composite film also has excellent selectivity and good overall physical and mechanical properties. This study provides a meaningful reference for the detection of Au³⁺ and further expands the application field of agroforestry waste.