Novel rhodamine probe for colorimetric and fluorescent detection of Fe3+ ions in aqueous media with cellular imaging

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 242; p. 118757
• Main Authors: Shellaiah, Muthaiah, Thirumalaivasan, Natesan, Aazaad, Basheer, Awasthi, Kamlesh, Sun, Kien Wen, Wu, Shu-Pao, Lin, Ming-Chang, Ohta, Nobuhiro
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.12.2020
• Subjects: Colorimetric recognition; Fluorescent “turn-on”; Nanomolar detection; Photoinduced energy transfer; Reversible Fe3+ sensor; Rhodamine-pyridine conjugate; Photoinduced energy transfer; Rhodamine-pyridine conjugate; Fluorescent “turn-on”; Nanomolar detection; Colorimetric recognition; Reversible Fe3+ sensor
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2020.118757

A novel rhodamine-pyridine conjugated spectroscopic probe RhP was synthesized and its X-ray single crystalline properties were revealed with tabulation. The RhP displayed a distinct pale-pink colorimetric and “turn-on” fluorescent response to Fe3+ in aqueous media [H2O:DMSO (95:5, v/v)] than that of other interfering ions. During the Fe3+ recognition, the absorption (UV–Vis) and photoluminescence (PL) spectral studies revealed new peaks at 561 and 592 nm, respectively. The 1:1 stoichiometry and binding sites were verified by Job's plot, ESI-mass, and 1H NMR titrations. Subsequently, LOD and binding constant for RhP + Fe3+ complex were estimated as 102.3 nM and 6.265 × 104 M−1 from linear fitting and Benesi-Hildebrand plots, correspondingly. Sensor reversibility of RhP + Fe3+ by EDTA was demonstrated by UV/PL and TRPL investigations. Moreover, the photoinduced energy transfer mechanism and band gap changes were established from the DFT interrogations. Lastly, cellular imaging studies were carried out to authenticate the real applicability of RhP in Fe3+ detection. [Display omitted] •Novel rhodamine spectroscopic probe RhP was synthesized via one pot reaction.•For the first time, single crystalline properties of RhP are delivered.•RhP show colorimetric/fluorometric selectivity to Fe3+ with negligible interference.•A PET based sensing mechanism has been validated by DFT studies.•Detection and reversibility of Fe3+ were demonstrated by cell imaging and TRPL studies.