A Multi‐signal Fluorescent Probe with Multiple Binding Sites for Simultaneous Sensing of Cysteine, Homocysteine, and Glutathione

Abstract

An ovel fluorescent probe was developed by integrating chlorinated coumarin and benzothiazolylacetonitrile and exploited for simultaneous detection of cysteine (Cys), homocysteine (Hcy), and glutathione (GSH). Featuring four binding sites and different reaction mechanisms for different biothiols,t his probe exhibited rapid fluorescence turn-on for distinguishing Cys,H cy,a nd GSH with 108-, 128-, 30-fold fluorescence increases at 457, 559, 529 nm, respectively,across different excitation wavelengths.F urthermore,t he probe was successfully applied to the fluorescence imaging of endogenous Cys and GSH and exogenous Cys,H cy,a nd GSH in living cells.

A fluorescent probe for the dual detection of mercury ions and thiols based on a simple coumarin derivative

“…Thus the conclusion was reached that the E1 probe is useful for fluorogenic detection of Hg(ii) over a relatively wide pH range of pH 4-11. Changes in the fluorescence emission spectra of the E1 probe (20 µmol/L) upon addition of different amounts of Hg(ii) (0, 1,2,4,8,12,16,20,40 and 60 µmol/L) were measured ( Figure 5). It was found that with increasing amounts of Hg(ii) added to E1 that the intensity of the fluorescence emission band at 466 nm decreased gradually, and that the intensity of the emission peak at 395 nm increased.…”

“…The fluorescence quenching effect of a thiol on probe E1 was further demonstrated by measurement of the change in the fluorescence emission spectrum of probe E1 upon the addition of one equivalent of p-toluenethiol in HEPES buffer (0.1 mol/L, pH = 7.16) with water/ethanol (9:1, v/v) as solvent(Figure 7). The results indicated that E1 can serve as a fluorescence turn-off sensor for the detection of thiols, in contrast to most other reported probes which were capable of sensing thiols by fluorescence enhancement [1][2][3][4][5][6][7].…”

“…Biothiols represented by cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) play fundamental roles in living systems, and the design of fluorescent probes for the selective detection of biothiols has attracted growing interest. [1][2][3][4][5][6][7] Thiophenols, which are also called benzenethiols, are extensively utilised in the synthesis of various products including pharmaceuticals, pesticides and polymers. However, thiophenols are a highly toxic and pollutant species.…”

Detecting Cysteine in Bioimaging with a Near‐Infrared Probe Based on a Novel Fluorescence Quenching Mechanism

“…Recently, many efforts have been devoted to exploiting highly selective fluorescent probes constructed on various traditional fluorophores to distinguish Cys from Hcy and GSH. [15,16,[19][20][21][22][23][24][25][26][27] Despite significant advances, a great number of these fluorescent probes exhibited absorption and emission in the ultraviolet or visible-light range, which may be strongly interfered by biological autofluorescence. [13][14][15][16][17][18] On the other hand, near-infrared region (650-900 nm) fluorescent probes emissive have been developed for biothiols in favour of the advantages of minimal damage, less light scattering, deep tissue penetration, and low background interference.…”

“…Owing to their closely related chemical activities, selective detection/visualization of a single thiol analyte with clear discrimination against other biothiol species remains a great challenge. Recently, many efforts have been devoted to exploiting highly selective fluorescent probes constructed on various traditional fluorophores to distinguish Cys from Hcy and GSH [15,16,19–27] . Despite significant advances, a great number of these fluorescent probes exhibited absorption and emission in the ultraviolet or visible‐light range, which may be strongly interfered by biological autofluorescence [13–18] .…”