A chromenoquinoline-based fluorescent off–on thiol probe for bioimaging

Abstract

A new chromenoquinoline-based fluorescent off-on thiol probe 2 is reported. In aqueous buffer solutions at physiological pH, the probe exhibited 223-fold enhancement in fluorescence intensity by a Michael addition of cysteine to the maleimide appended to a chromenoquinoline. Cell permeability and live cell imaging of thiols are also demonstrated.

A Novel Ratiometric Two‐Photon Fluorescent Probe for the Detection of Biothiols in Solution and Imaging of Living Cells

“…[2] So far, a large number of fluorescent molecular probes have been exploited that mainly function through various chemical reactions with thiols to trigger the corresponding spectral alterations; examples are the Michael reaction, [3] cyclization reaction with an aldehyde, [4] and cleavage reaction by thiols, [5,6] among others. [7] The majority of these probes are based on a turn-on fluorescence response in which the fluorescence is measured at a single wavelength and may be influenced by variations in probe concentration and the environment.…”

An off–on fluorescent probe based on maleimide for detecting thiols and its application for bioimaging

“…S5). Probe 1 shows a high sensitivity towards thiols which is comparable to other reported thiol probes [20,30,60] (Table 1) and can be applied to quantitative measurement of thiol concentration.…”

“…Especially in recent years, Michael addition type probes for thiols have been the focus of increasing attention. A number of excellent Michael acceptors such as maleimide [19][20][21][22][23][24][25], chromene [26][27][28][29][30][31], squaraine [32][33][34], acrylic acid [35][36][37][38], as well as ␣,␤-unsaturated aldehyde [39,40], ketone [41][42][43][44][45], diesters [46,47], malonitrile [48] and nitro compound [49][50][51] have been exploited for the design of thiols fluorescent probes. Although many promising results have been reported for thiols detection in recent years, there is still a need for improving methodology for this purpose.…”

A New Turn on Fluorescent Probe for Selective Detection of Cysteine/Homocysteine

“…Significant efforts have been devoted to construction of fluorescent probes for biothiols [7]. Many fluorescent probes involved in different detecting mechanisms have been developed for thiols detecting, such as Michael addition reaction [8][9][10][11][12][13][14][15][16], cyclization reaction based on aminothiols and aldehyde [17][18][19][20][21], cleavage reaction induced by thiols [22][23][24][25][26][27][28][29][30], and ligand displacement of metal complexes by thiols [31][32][33].…”