Low-cost paper-based fluorescent sensor functionalized with a PVC-metal-morin complex for the determination of Zn(II)...

In this research, a paper-based fluorescent sensor functionalized with the PVC-Metal-Morin complex was developed for the detection and quantification of Zn(II) and Al(III) ions in environmental samples. The sensor was designed with a focus on low cost, simplicity, portability, and sustainability, employing accessible materials and a practical methodology suitable for contexts with limited laboratory infrastructure. The fluorescent Metal-Morin complex was synthesized and incorporated into a PVC polymeric matrix, which was immobilized onto filter paper, resulting in a sensitive and regenerable sensor. The material was characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS), confirming the formation and adhesion of the complex to the cellulosic matrix. The sensor exhibited high selectivity and strong fluorescent response toward Zn(II) and Al(III) ions, even in the presence of interfering ions such as Fe(III), Cu(II), Cd(II), and Pb(II). Additionally, the sensor showed good linearity (R² > 0.99), with limits of detection of 0.0061 mg L^-1 for Zn(II) and 0.0089 mg L^-1 for Al(III). Precision tests revealed relative standard deviations (RSD) below 5%, while accuracy assays, expressed as recoveries, ranged from 97.0% to 109.5%. The environmental performance of the method was assessed using the AGREE metric, yielding a score of 0.76. The sensor also demonstrated stability and regeneration capability and was successfully applied to the analysis of various environmental samples.