A zwitterionic probe for ratiometric fluorescent detection of aluminium(III) ion in aqueous medium and its application in bioimaging

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2024-04, Vol.311, p.124005, Article 124005
• Main Authors: Sanaul Islam, Md, Hoque, Anamika, Mohamed Yusuf Baig, K., Sarmin, Monalisha, Kole, Goutam Kumar, Hoda, Muddasarul, Akhtarul Alam, Md
• Format: Article
• Language: English
• Subjects: Al3+ ion detection; Aqueous solution; Crystal structure; Ratiometric fluorescent detection; Test Kit; Zwitterion
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2024.124005

The compound 1 can selectively recognize Al3+ ion with significant ratiometric fluorescent enhancement. [Display omitted] •Crystal structure of zwitterionic Schiff base.•Zwitterionic Schiff base soluble in water.•Ratiometric fluorescent probe for selective detection of Al3+ ion in aqueous medium.•Application of zwitterionic Schiff base. In the present study, we have synthesized an aminobenzoic acid containing Schiff base (compound 1) and its structure was confirmed through single crystal X-ray study. Importantly, the compound 1 crystallizes in the zwitterionic form, with an anionic carboxylate group (–COO−) and a cationic iminium group (–C = NH+–). The compound 1 is highly soluble in water due to its zwitterionic feature in the solid state. Interestingly, compound 1 acts as a ratiometric fluorescent probe for the selective detection of Al3+ ion in aqueous solution without organic cosolvent. It can also detect Al3+ ion by visual colour change to bluish-green fluorescence under 365 nm UV light. The association constant between compound 1 with Al3+ ion was estimated to be 1.67 × 104 M−1. The lowest detection limit for Al3+ ion was calculated to be 7.05 × 10−8 M in water. Compound 1 in combination with Al3+ ion demonstrated fluorescent imaging potential of the nucleus of in RAW 264.7 murine macrophage cell line. In addition, the sensing model is developed as paper based sensor ''Test Kit' 'for its practical applicability.