Selective Turn‐On Aluminium Ions Detection of NBD⁽⁺⁾ Appended Schiff‐Base Fluorophore

Abstract

The Al3+ sensor, 7‐nitrobenz‐2‐oxa‐1, 3‐diazole (NBD) derived fluorescent probe 2‐((E)‐(4‐(phenylamino)benzo[c][1,2,5]oxadiazol‐7‐ylimino)methyl) phenol (3) was synthesized and characterized by various spectral methods and crystallography. The compound (3) exhibits dual channel (fluorometric and colorimetric) sensor behaviour. It has high selectivity for Al3+ detection, produced significant fluorescence enhancement in the presence of Al3+ ion. It shows ‘‘turn off–on’’ fluorescent responses toward Al3+ in semi aqueous medium. Here, the correlative the properties of a photo sensor (NBD based schiff‘s base 3 with normal NBD derivatives 1, 2) towards Al3+ was studied. The solvent effect and cation sensing properties were investigated from ultraviolet spectroscopy and fluorescence spectroscopic methods. The facile synthetic probe 3 will alternative and open new opportunities in bio‐imaging of Al3+ in various cell lines. This will certainly be helpful in understanding the fundamental mechanism of aluminium‐induced human diseases.

Visible light‐triggered pyrazole‐functionalized reversible ionophore for selective monitoring of aluminium (III) ion

“…With Al 3+ , the interaction of S1 and Al 3+ becomes unnavigable to the PET and ESIPT processes, thereby turning on the remarkable fluorescence properties at 536 nm for S1 . The recently reported observations by Peng et al, [ 48 ] Keskin et al [ 49 ] and Balagurusamy et al [ 50 ] strongly support this mechanism for the CHEF driven turn‐on fluorescence for Al (III) ion recognition in solution. We surveyed the literature and made a comparison of detection efficiency (association constant) and detection limit with the reported structures (Table 2) [ 50–61 ] to understand the proficiency of the probe for selective detection of aluminium ions.…”

Photometric and Colorimetric Cyanide Detection Sensor Using Amine Based Nitrobenzoxadiazole Derivatives

“…The synthetic scheme of the fluorescence probes 1 and 2 are shown in scheme 1 and 2. Probe 1 crystal structure had reported earlier by our group [14] . As depicted in Scheme 2, NBD−Cl was treated with 4‐amino benzonitrile to afford the desired Probe 2 as a red coloured solid (yield: 70.0 %).…”

“…Probe 1 crystal structure had reported earlier by our group. [14] As depicted in Scheme 2, NBDÀ Cl was treated with 4-amino benzonitrile to afford the desired Probe 2 as a red coloured solid (yield: 70.0 %). These Probes were confirmed by 1 H & 13 C NMR, and HR-MS (see ESI, Figure S1-S6).…”

Acridino-Diaza-20-Crown-6 Ethers: New Macrocyclic Hosts for Optochemical Metal Ion Sensing

“…The recently published Al 3+ -selective optochemical sensors [ 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ] were similarly compared. Due to the similar atomic radius and valence to Mg 2+ , Ca 2+ and Fe 3+ , Al 3+ can act as a competitive inhibitor of these ions in biological processes [ 34 ] and can also induce neurodegenerative disorders [ 41 ].…”

“…It appears that the majority of Al 3+ -sensors show similar characteristics in operation—i.e., in the applied semi-aqueous medium, similar association constants (log K = 3.5–7.5) and low limits of detection (6.0 × 10 −6 M–2.7 × 10 −8 M), below the tolerance limit in drinking water (~7.4 × 10 −6 M [ 42 , 43 ]) —as those reported for Zn 2+ -selective ones [ 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. Unfortunately, the selectivity of the reported sensor molecules is often limited due to the interference of other cations, which were typically Ni 2+ [ 28 , 31 ], Cu 2+ [ 30 , 31 , 32 , 40 ], Hg 2+ [ 30 , 32 ], Fe 2+ [ 31 ], Mg 2+ [ 36 ], and especially trivalent ions like Cr 3+ [ 30 , 36 , 40 ]. In the case of Al 3+ -sensors, the study of pH-dependence is of high importance as Al 3+ acts as a Lewis acid in water, thus adding it into a sample solution definitely results in a change of pH, which affects the photophysical behavior of the chemosensors.…”