Efficient dual sensor based on modified NH2-UiO-66(Zr) MOF for sensitive and rapid monitoring of ultra-trace arsenic (III) in aqueous media

Abstract

This research aimed to develop a new zirconium-based sensitive material called the 5Cl2HA=(Zr) MOF sensor. The sensor was created by condensing 5-Chloro-2-hydroxyacetophenone with NH2-UiO-66(Zr). Its effectiveness, selectivity, and sensitivity were demonstrated by successfully detecting ultra-trace concentrations of As3+ ions in real water samples using spectrophotometric and fluorometric methods. The characterization of the 5Cl2HA=(Zr) MOF sensor involved various techniques, including SEM, XRD, XPS, BET, and FT-IR, which confirmed its successful synthesis and provided insights into its structural and surface properties. Optimization experiments were conducted to determine the best conditions for detecting As3+ ions using colorimetric and fluorometric methods. The sensor exhibited a rapid detection capability, achieving a stable spectroscopic signal in less than 10 s. The proposed methods adhered to (ICH) guidelines, and parameters such as precision, the limit of detection (LOD), the limit of quantification (LOQ), and linearity were evaluated. The spectrophotometric technique demonstrated the lowest LOD for As3+ ions, with a value of 0.0607 ppm. The recyclability of the sensor was investigated, showing successful reuse up to five times with 85% efficiency by employing 0.01 M HCl as the eluent for regeneration. Furthermore, the performance of the 5Cl2HA=(Zr) MOF sensor was evaluated using various real samples, including groundwater and city water samples, demonstrating high sensitivity and selectivity in detecting As3+ ions in these complex matrices. These findings highlight the sensor's potential for real-world applications.