Rapid and Efficient Dual Detection Of Zn 2+ Ions and Oxytetracycline Hydrochloride Using a Responsive Fluorescent "On-Off" Sensor Based on Simple Salen-Type Schiff Base Ligand

This research has progressed to an effective detection chemosensor of zinc, aluminum ions and oxytetracycline hydrochloride antibiotic based on the fluorescence technique. A straightforward method utilizing microwave irradiation was employed to synthesize the salen-type Schiff base ligand N,N'-bis(salicylaldehyde)4,5-dichloro-1,2-phenylenediamine (H I), providing a good 70 % yield. In ethanol, the H I sensor demonstrated remarkable rapidity, selectivity, and sensitivity in detecting zinc ions. The fluorescence spectrum exhibited a 44-fold substantial enhancement at 522 nm and achieved a low limit of detection (LOD) of 1.47 μM. Furthermore, the H I probe's emission intensity increased by 124 times when compared to the ligand's ability to detect Al ions at 494 nm with a LOD value of 7.4 μM. Additional research was done using the H I probe's effective Zn detection capability. The ability to recognize zinc ions in different real water samples demonstrated a recovery rate of 98.67 % to 103.31 %. Interestingly, a naked-eye visible fluorescence color of H I solution impregnated filter papers turned colorless into yell ow under UV irradiation by adding Zn ions, renders it suitable for developing a practical zinc ion detection kit test. In particular, the I-Zn complex effectively quenched the fluorescence toward oxytetracycline hydrochloride (OTC) with a LOD value of 1.49×10 μM in DMSO:H O (6 : 4, v/v). This is a novel and effective procedure for sensing OTC antibiotic by the I-Zn complex. These findings hold immense potential for the development of dual fluorescent probes, thereby enhancing sensitivity and specificity in identifying metal ions and antibiotics in a wide range of applications.