Functionalized MOF as a Sensitive Spectroscopic Probe for Hg²⁺, Co²⁺, and Al³⁺ Ions Detection in Aqueous Media

Abstract

A modified metal–organic framework (MOF) named Al-MIL-53-N=SA-Br was synthesized via a Schiff-base reaction between the MOFs (Al-MIL-53-NH 2 ) and 5-bromo salicylaldehyde. The robust functionalized Al-MIL-53-N=SA-Br was used as a novel spectrophotometric sensor for detecting Hg 2+ , Co 2+ , and Al 3+ ions. In a wide range of concentrations, the absorption spectral intensity of Al-MIL-53-N=SA-Br increased linearly upon increasing the concentration of Hg 2+ , Co 2+ , and Al 3+ ions. The limit of detection (LOD) of the proposed Al-MIL-53-N=SA-Br sensor reached 1.52 ppm of Hg 2+ ion (7.56 × 10 –9 M). Therefore, this study introduces a novel ratiometric Hg 2+ , Co 2+ , and Al 3+ ions chemosensor. Simple treatment using thiourea or ethylenediaminetetraacetic acid can remove the metal ions from the used sensor and use it many times with a high efficiency. In addition, the Al-MIL-53-N=SA-Br sensor has a high adsorption capacity for these metal ions. The design of the robust Al-MIL-53-N=SA-Br sensor provided high stability, reproducibility, selectivity, high sensitivity, and a facile sensing design. Furthermore, the good absorption spectral stability of Al-MIL-53-N=SA-Br in aqueous media, the broad linear in sensing, and the low LOD of the Hg 2+ , Co 2+ , and Al 3+ ions show its high potential in determining these ions in real water.

Selective recognition of Hg2+ ions in aqueous solution by a CdII-based metal–organic framework with good stability and vacant coordination sites

“…3d). Compared with several sensors previously used for the determination of Hg 2+ , 21–30 the detection limit of the JXUST-28 sensor was found to be at a low level (Table S5, ESI†).…”

“…20 The stable MOF materials are rich in pore surfaces and functional sites, which can be used for the detection and removal of mercury ions from wastewater. [21][22][23][24][25][26][27][28] For example, Wang and his colleagues designed a dual functional material (NH 2 MIL-53(Al)) for the adsorption and removal of Hg 2+ ions with a limit of detection (LOD) of 0.15 μM. 29 Yang and coworkers report a Sm III -MOF derived from 2-aminoterephthalic acid for the removal and detection of Hg 2+ ions, which has excellent selectivity and high sensitivity with a wide linear range of 0.6-300 μM and a LOD of 0.87 μM.…”

A zeolitic imidazolate framework-90-based probe for fluorescent detection of mitochondrial hypochlorite in living cells and zebrafish

“…[11][12][13][14][15][16] More recently, metal-organic frameworks (MOFs) with geometrically well-defined structures have attracted substantial attention in the fields of biomedicine and biosensors. [17][18][19][20][21] Besides, zeolitic imidazolate framework-90, derived from Zn 2+ and an imidazole-2-carboxaldehyde (2-ICA) ligand, has been widely used in ATP imaging, owing to its distinct chemical stability and excellent biocompatibility, as well as mitochondria-targeting ability. 17 Moreover, the covalent functionalization of the free aldehyde groups in the ZIF-90 framework is easily achieved, supporting its role as a fluorometric sensor.…”

Design, synthesis and evaluation of liver-targeting fluorescent probes for detecting mercury ions

“…12 Fluorescent probes have recently received extensive attention from academia and industry 13,14 because these sensors can quantitatively detect Hg 2+ 15,16 with good selectivity, high sensitivity, and low detection limit and are simple to operate at relatively low cost. 17–19 It has been reported that fluorescence sensors have been used to study the biochemical processes related to Hg 2+ in organisms, 20,21 which has promoted the development of non-invasive approaches. 22,23 Recently, Chung et al 24 integrated platinum( ii ) terpyridine and dithiaazacrown, exhibiting a metal-to-ligand charge transfer transition and an internal charge transfer transition to realize a dual channel sensing mode, which could detect low concentrations of Hg 2+ .…”