Cation-Exchange in Metal-Organic Framework as a Strategy to Obtain New Material for Ascorbic Acid Detection

Abstract

Ascorbic acid (AA) is an important biomolecule, the deficiency or maladjustment of which is associated with the symptoms of many diseases (e.g., cardiovascular disease or cancer). Therefore, there is a need to develop a fluorescent probe capable of detecting AA in aqueous media. Here, we report the synthesis, structural, and spectroscopic characterization (by means of, e.g., XRD, XPS, IR and Raman spectroscopy, TG, SEM, and EDS analyses), as well as the photoluminescent properties of a metal‒organic framework (MOF) based on Cu2+ and Eu3+ ions. The ion-exchange process of the extraframework cation in anionic Cu-based MOF is proposed as an appropriate strategy to obtain a new material with a nondisturbed structure and a sensitivity to interaction with AA. Accordingly, a novel Eu[Cu3(μ3-OH)(μ3-4-carboxypyrazolato)3] compound for the selective optical detection of AA with a short detection time of 5 min is described.

A new MOF@bioactive glass composite reinforced with silver nanoparticles – a new approach to designing antibacterial biomaterials

“…Interestingly, the ion-exchange processes of the extraframework cations can modulate the textural properties and thus influence the adsorption selectivity of various separation processes of gases and vapors or open up new application possibilities. 32,38 The synthesized NH 4 [Cu 3 (μ 3 -OH)(μ 3 -4-carboxypyrazolato) 3 ] MOF was systematically characterized by PXRD and ATR-FTIR, confirming the purity of the isolated material (Fig. S2 †).…”

“…The presence of micro- and mesopores was also typical of pristine Cu-MOF. 38 However, it can be noted that the anchored AgNPs markedly modulated the porosity of the Cu-MOF. The BET surface area and pore volume decreased twice from 476 m 2 g −1 and 0.22 cm 3 g −1 for Cu-MOF 38 to 230 m 2 g −1 and 0.10 cm 3 g −1 for Ag@Cu-MOF, respectively.…”

Stability of Zr-Based UiO-66 Metal–Organic Frameworks in Basic Solutions

“…Finally, inductively coupled plasma–optical emission spectrometry (ICP-OES) analysis was conducted to examine the metal-to-ligand ratio of the MOF following the base treatment. Given that the general formula of UiO-66 MOF is Zr 6 O 4 (OH) 4 (BDC-ligand) 6 , the dissolution of the ligand in a basic solution could lead to an increase in the metal ratio [ 72 , 73 , 74 ]. While UiO-66 exhibits a theoretical zirconium content of 32.9 wt%, the pristine UiO-66 (as-synthesized form) contains 34.0 wt% due to structural defects.…”

A Water‐Stable Europium Metal‐Organic Framework as a Turn‐Off Fluorescence Sensor for Ascorbic Acid Detection in Human Serum

“…Compared to those methods, fluorescence with the features of rapid response, easy operation, and high sensitivity is as a simple and convenient tool for monitoring AA, attracting much attention. The fluorescence materials cover nanomaterials, [8][9][10] enzyme, [11] metal-organic frameworks (MOFs), [12][13][14][15] and etc. MOFs or coordination polymers are an important material source of fluorescence sensors.…”