Quinoline Driven Fluorescence Turn On 1,3-Bis-calix[4]arene Conjugate-Based Receptor to Discriminate Fe³⁺ from Fe²⁺

Abstract

The synthesis and characterization of a triazole linked quinoline appended calix[4]arene conjugate, L, and its fluorescence turn on receptor property for Fe(3+) have been demonstrated. The selective and sensitive discrimination of Fe(3+) has been shown using fluorescence and absorption titration experiments. The Fe(3+) binding to L has been further shown by ITC and ESI MS. The mode of binding of Fe(3+) by calix[4]arene conjugate has been shown by absorption, (1)H NMR and visual color change and the species were modeled based on DFT computations. The {L + Fe(3+)} has been shown to label cells with fluorescence imaging. Moreover the utility of this conjugate has been demonstrated by the combination logic gate system.

A ppb level turn-on fluorescence chemosensor for the detection of Zn2+

“…The detection limit of DMPSQ was calculated to be 80 ppb (1.2 nM) in ethanol, which was derived by using the formula 3σ/k where σ stands for the standard deviation of the blank samples and k is the slope of linear fit curve. [13,15] The 80 ppb detection limit also verified by experiment, as shown in the inset of Fig. 5(b).…”

Recent Advances on Iron(III) Selective Fluorescent Probes with Possible Applications in Bioimaging

“…The probe showed a LOD of 1.3 × 10 −7 M and was applied for the detection of intracellular Fe 3+ ions in living HCT-116 cells. Using the Calix [4] arene framework, the quinoline-appended dipodal fluorescent probe 42 has been developed, and its cations sensing ability has been examined in CH 3 CN [49]. Upon complexation of Fe 3+ with 42 in 1:1 binding ratio, significant fluorescence enhancement has been observed at 418 nm (λ exc = 310 nm), and the LOD of 0.334 μM Fe 3+ has been estimated from the fluorescence titration experiment.…”

Synthesis, Complexation and DFT Computational Studies of Bis(naphthyl)methane‐“Capped” Triazole‐Linked Calix[4]arenes as Fe3+ Fluorescent Chemosensors

“…The selectivity of 5 a towards Fe 3+ was examined using competitive fluorescence experiments in which up to one molar equivalent of ferric ions were added to each of the respective solutions in which the mole ratios of the various individual metal ions were kept constant at a 1:10 ratio with respect to 5 a . The concentrations of the individual metal ions were 1.50 x 10 −4 M and that of 5 a was 1.50 x 10 −5 M. The histogram shown as Figure shows the quenching of the fluorescence spectra of 5 a by the addition of the Fe 3+ and shows that 5 a is more selective for Fe 3+ with the exceptions of Cu 2+ and Hg 2+ for which there were very small quenching.…”