A Water-soluble Near-infrared Fluorescent Probe for Cysteine/ Homocysteine and Its Application in Live Cells and Mice

Abstract

A near-infrared (NIR) and water-soluble probe was synthesized and studied for the detection of Cys/Hcy in aqueous solution, living cells and mice. The probe was composed of cyanine derivative as the NIR fluorescent reporting unit and pyrimidiny-thioether moiety as the Cys/Hcy responsive unit. Treatment with Cys/Hcy induced the formation of sulfur-substituted products, then intramolecular rearrangement reaction would occur to produce amino-substituted products and resulting in enhanced red fluorescence emissions. It could be applied to sense Cys/Hcy both in solution with the detection limit of 0.17 μM (or 0.32 μM) and in living cells. Cell imaging experiments proved that such a probe exhibited good cell penetration. In addition, the probe could detect Cys/Hcy in live mice with strong turn-on fluorescent response.

Fluorescent probes based on nucleophilic aromatic substitution reactions for reactive sulfur and selenium species: Recent progress, applications, and design strategies

“…There are many small aromatic molecules that can bind to fluorophores and are attacked by RSS or RSeS. Below, we describe some unusual cases [243] , [244] , [245] , [246] .…”

Recent Progress of Near-Infrared Fluorescence in vivo Bioimaging in the Second and Third Biological Window

“…Recently, near-infrared (NIR) fluorescence imaging has attracted attention of particularly biologists and medical scientists, since NIR light (> 700 nm) can penetrate tissues. [1][2][3][4][5] As compared to the short-wavelength ultraviolet (UV: < 400 nm) or visible (VIS: 400 -700 nm) region, which results in low absorption or scattering of biomolecules and water in the body, NIR light passes through the tissues. Thus, the NIR wavelength region (700 -1800 nm) is referred to as the "biological window" and is used for bioanalysis.…”

BODIPY-based Fluorescent Probe for the Detection of Cysteine in Living Cells

“…[16][17][18] In recent years, a large number of fluorescent indicators have been developed to distinguish and measure thiols by taking advantage of the strong nucleophilicity of the thiol group. [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] Despite significant progress achieved to selectively distinguish thiols from other amino acids, most of the methods suffer from the limitation of differentiation of Cys, Hcy, and GSH from each other due to the similar structures and reactivities of these thiols. Consequently, we are intent on designing and synthesizing novel fluorescence sensors that can effectively discriminate Cys, Hcy and GSH.…”