A multifunctional tripodal fluorescent probe for the recognition of Cr3+, Al3+, Zn2+ and F− with controllable ESIPT processes

Abstract

Three 4- (benzo[d]thiazol-2-yl)-2,5-dihydroxybenzaldehyde fluorophores were introduced to construct a tripodal multifunctional ESPIT fluorescence probe L. The fluorescent analysis revealed that probe L exhibited excellent recognition capability towards Cr 3+ , Al 3+ , Zn 2+ and Fions with large Stokes shift. Furthermore, under the optimal conditions, the detection limit of probe L towards Cr 3+ , Al 3+ , Zn 2+ and Fwere low, of the order of 10 -8 M, which indicated that probe L was sensitive to these four ions. Interestingly, the fluorescent and 1 H NMR titration experiments revealed that the recognition mechanism of probe L towards the ions Cr 3+ , Al 3+ , Zn 2+ and Fwere different. The presence of Cr 3+ and Al 3+ recovered the ESIPT, but the presence of Zn 2+ trigger a moderate deprotonation of the phenolic OH and induced an ESIPT red shifted (60nm) emission wavelength. Finally, the presence of Fcompletely deprotonated the free phenolic OH and a remarkable red shifted (130 nm) ESPIT emission was observed. In other words, the ESIPT process of probe L is controllable. Furthermore, the utility of probe L as a biosensor in living cells (PC3 cells) towards Cr 3+ , Al 3+ and Zn 2+ ions has been demonstrated.

Red/Green Tunable-Emission Carbon Nanodots for Smart Visual Precision pH Sensing

“…This suggested that there were two kinds of emission sites in CDs 1 . Typical, ratiometric changes are considered to be the most accurate fluorescence detection method due to the self-calibration for environmental disturbance by two well-resolved wavelengths (Figure b (inset)). ,, However, UV–vis absorption spectra of CDs 1 under different pH conditions have been recorded (Figure S11). In contrast with the fluorescence spectra, no obvious changes were observed in the UV–vis absorption spectrum of the CDs as the pH increased from 1 to 14, which demonstrated that there was no ground-state complex formation.…”

A Light‐Up Fluorescent Probe for Detection of Formaldehyde in Serum and Gaseous Based on d‐PeT Process

“…Small organic fluorophores are indispensible tools for the construction of fluorescent probes because of the controllable optical properties such as bodipy, coumarin, rhodamine, fluorescein, etc . Among them, fluorophores derived from benzothiazole are widely used as the dye platform for designing of fluorescent probes . In our previous work, a ratiometric fluorescent probe HBT‐FA for sensing formaldehyde based on intramolecular charge transfer (ICT) mechanism by using aza‐cope reaction was constructed, which showed good ratio signals in aqueous and calf serums .…”

Preparation of anthracene-based tetraperimidine hexafluorophosphate and selective recognition of chromium(III) ions

“…Generally, chemosensors with fluorescence enhancement are more efficient than fluorescence turn-off chemosensors [24–29] because the paramagnetic nature of chromium(III) can cause fluorescence quenching of the fluorophore via the enhancement of spin–orbit coupling [30–35]. So far, only a few successful examples of fluorescence enhancement sensors for Cr 3+ have been reported [36–40]. Thus, developing new and effective fluorescence turn-on chemosensors for Cr 3+ is necessary.…”