Search

The abnormality of Cys concentration in organism could lead to a series of diseases, so its effective detection is of great importance in disease diagnosis. Here we developed a novel ESIPT fluorescent probe HBT-IDAc based on the classic ESIPT fluorophore 2-(2′-hydroxyphenyl)benzothiazole (HBT) and indanone, which could selectively and sensitively detect Cys with a large Stokes shift up to 210 nm and the detection limit to 0.89 μM. In addition, the probe exhibited good anti-interference and low cytotoxicity, and has been successfully applied to monitor Cys in cells. • A novel ESIPT fluorescent probe for selective and sensitive detection of Cys was developed. • The probe has the large stokes shift (210 nm) and good LOD (0.89 μM) in aqueous environment. • The probe exhibits low cytotoxicity and has been applied for imaging Cys in cells. [ABSTRACT FROM AUTHOR]

Mercury ion (Hg2+) is highly toxic to the environment and organisms, therefore, monitoring and quantitative detection of Hg2+ is of great significance. In this work, a new fluorescent probe TPEH that integrated tetraphenylethene (TPE) and 2-(2 ′ -hydroxyphenyl)benzothiazole was designed and synthesised. In EtOH/HEPES (2:8, v/v, pH = 7.2) solution, TPEH displays fluorescence turn on detection of Hg2+ with the advantages of swift response (<100 s), high selectivity and strong disturbance-resistant, a large Stokes shift (220 nm), and low limit of detection (81.7 nM). The sensing mechanism was proved to be Hg2+-triggered releasing of the aggregation-induced emission (AIE)-active precursor compound 2. TPEH has been successfully applied to detect Hg2+ in seafood and tea, and image Hg2+ in living cells. In addition, TPEH can be used to detect the content of Hg2+ in actual water samples with the aid of smartphone. [Display omitted] • A new AIE-based fluorescent probe TPEH for Hg2+ detection has been developed. • TPEH has the advantages of rapid response (<100 s), a large Stokes shift (220 nm), and a low detection limit (81.7 nM). • TPEH can detect Hg2+ in seafood and tea, and image Hg2+ in living cells. • TPEH can detect Hg2+ in actual water samples with the help of smartphone. [ABSTRACT FROM AUTHOR]

Abstract A new imidazo [1,5- a ]pyridine-based fluorescent probe, named MZC-AC, is developed for the detection of cysteine (Cys) based on an excited state intramolecular proton transfer (ESIPT) mechanism. The probe MZC-AC uses an acrylate moiety as the ESIPT blocking group as well as the recognition site. Upon the treatment with Cys, MZC-AC exhibits a dramatic fluorescence enhancement (85-fold) and a large Stokes shift (166 nm). The limit of detection obtained from fluorescent titration was as low as 0.07 μM. MZC-AC displays highly sensitive and selective response to Cys over homocysteine (Hcy) and glutathione (GSH). Significantly, MZC-AC could be used to detect Cys in living cells. Graphical abstract Image 1 Highlights • An imidazo [1,5- a ]pyridine-based fluorescent probe MZC-AC was developed. • MZC-AC can detect cysteine with high sensitivity and selectivity. • MZC-AC shows a large Stokes shift. • The limit of detection was as low as 0.07 μM. • MZC-AC can be applied in imaging intracellular cysteine in living cells. [ABSTRACT FROM AUTHOR]

The abnormal expression of cytochrome P450 2J2 (CYP2J2) is closely related to the proliferation of human cancer cells. In this study, a red-emitting probe with an aggregation-induced emission (AIE) effect for the quantification of CYP2J2 was developed by modifying the typical AIE fluorescent group tetraphenylethylene (TPE) through two-step synthesis. Upon addition of CYP2J2, the probe underwent O-demethylation and spontaneously 1,6-elimination reactions of p-hydroxybenzyl that allowed it to alter its photophysical properties, thus realizing light-up detection of CYP2J2 with extremely large Stokes shift (236 nm), excellent sensitivity and selectivity, low detection limit (1.09 nM). Moreover, this new AIE-active probe with good biocompatibility was admirably employed to tracking endogenous CYP2J2 in living cells. • An AIE-based fluorescent probe (TPE-Bn) was designed to detect CYP2J2. • This probe showed significant Stokes shift (236 nm), good photostability, excellent sensitivity and selectivity, and low cytotoxicity. • This probe can be used to visualize endogenous CYP2J2 in living cells and tissues. [ABSTRACT FROM AUTHOR]

A simple fluorescent probe (TPE-1) based on the combination of tetraphenylethene (TPE) and 2-(2′-hydroxyphenyl)benzothiazole (HBT) was synthesized. TPE-1 possesses both aggregation-induced emission (AIE) and excited-state intramolecular proton transfer (ESIPT) characteristics. The TPE-1 aggregates exhibited rapid (10 s) and highly selective recognition of Cu2+ in THF/H 2 O (1:9, v/v, HEPES 20 mM, pH = 7.4) solution, and was induced an "on-off" change in the fluorescence. TPE-1-Cu 2+ complexes generated in situ can also be used as sensing ensembles for highly selective detection of H 2 S by Cu2+ displacement. As a result, the fluorescence of TPE-1 was recovered again, and an "on-off-on" fluorescence variation was used to relay Cu2+ and H 2 S recognition. The detection limits of the probes for Cu2+ and H 2 S are 9.91 × 10−8 M and 3.80 × 10−7 M, respectively. In addition, the probes can be applied to detect Cu2+ and H 2 S in some food samples and can also be applied to cell imaging experiments. Relay recognition of Cu2+ and H 2 S by a fluorescent probe regulated by AIE and its application in food and cell imaging. [Display omitted] • An AIE-based fluorescent probe TPE-1 was designed and synthesized. • TPE-1 can relay identify Cu2+ and H 2 S with high sensitivity, high selectivity, large Stokes shift, and low detection limit. • TPE-1 can rapidly relay responses to Cu2+ and H 2 S with on-off-on fluorescence changes. • TPE-1 is suitable to assay the Cu2+ and H 2 S level in water, seafood, tea and red wine samples. [ABSTRACT FROM AUTHOR]

A series of fluorescent dyes based on 2-(2′-hydroxyphenyl)benzothiazole derivatives were designed and synthesized. Because of their structural characteristics of "AIE + ESIPT", they have long-wavelength emission and a larger Stokes shift. The fluorescent probe HBTN-Y was prepared based on the fluorescent dye HBTN. Probe HBTN-Y can recognize cysteine (Cys) with a high selectivity, "OFF-ON" fluorescence response, a large Stokes shift (263 nm) and long-wavelength emission (637 nm) in MeCN/H 2 O (1:1, v/v, PBS 20 mM, pH = 8.4) solution. The probe exhibits good anti-interference ability, a low detection limit of 6.51 × 10−6 M, and is suitable for application at near neutral and weak alkaline pH (7–9) conditions. Moreover, HBTN-Y is applicable to image Cys in living MCF-7 cells. A new fluorescence "AIE + ESIPT" characteristics probe HBTN-Y for the detection of cysteine has been developed. [Display omitted] • A series of fluorescent dyes with "AIE + ESIPT" features were synthesized. • A cascade reaction-based fluorescence "turn on" probe (HBTN-Y) has been developed. • HBTN-Y displays highly selective recognition for Cys in an aqueous solution. • HBTN-Y can detect Cys with a long wavelength emission and a large Stokes shift. • HBTN-Y is capable of imaging Cys in living MCF-7 cells. [ABSTRACT FROM AUTHOR]

In this work, we have developed a new carbazole-based fluorescent probe (E)-1-methyl-4-(2-(5-(9-phenyl-9 H -carbazol-3-yl) thiophen-2-yl)vinyl)pyridin-1-ium (PCTP) for ratiometric and colormetric ClO− sensing. PCTP displayed red emission due to the intramolecular charge transfer (ICT) effect of phenylcarbazol moiety, while this effect can be rapidly weakened and led to the significant fluorescence change (from red to green) in the presence of ClO−. PCTP is more highly selective and sensitive towards ClO− detection than other various biological related species. The detection limit (LOD) was calculated to be 10.8 nM. More importantly, PCTP has been successfully applied in ClO− imaging in living cells and zebrafishes. • A novel colormetric and ratiometric fluorescent probe (PCTP) was designed and synthesized for detecting ClO−. • PCTP displays a low detection limit (10.8 nM) and large Stokes shift (124 nm). • PCTP successfully performed well in sensing ClO− in living cells and zebrafishes. [ABSTRACT FROM AUTHOR]

Carbon monoxide (CO) is an important kind of gasotransmitter associated closely with pathogenesis of inflammation and detection of CO in living systems is of great attraction in recent years. To data, accurate fluorescent detection of CO in vivo is still challenging. In this study, we reported for a new simple NIR fluorescent probe CO–B with stable allyl ether as the specific CO-reactive site. The detection mechanism of this probe has been proven through the rearrangement of conjugated π-electron system. CO–B featured large Stokes shift (135 nm), low toxicity, good sensitivity (detection limit of ∼110 nM) and selectivity for CO detection. CO–B successfully served as an indicator for imaging CO in Heme-stimulation inflammation model. Finally, CO–B was also employed for in vivo imaging CO in living mice with low background interference. All together, probe CO–B was potentially valuable as a promising tool for monitoring and tracking CO in preclinical applications. Image 1 • A new stable NIR fluorescent probe CO–B for CO detection was reported. • CO–B was easy-to-get with only two step reactions. • CO–B featured large Stokes shift (135 nm), low toxicity, good sensitivity and selectivity for CO detection. • CO–B was successfully employed for imaging CO in cells and in living mice. [ABSTRACT FROM AUTHOR]