An FITC‐BODIPY FRET Couple: Application to Selective, Ratiometric Detection and Bioimaging of Cysteine

Abstract

A novel FRET couple of fluorescein is disclosed, and it was readily constructed by conjugating an amino-BODIPY dye, a new FRET donor, with fluorescein isocyanate. Its potential was demonstrated by a fluorescence sensing system for cysteine, which was prepared by introducing acryloyl groups to the fluorescein moiety. The FRET probe exhibited promising ratiometric response to cysteine with high selectivity and sensitivity in a buffer solution containing acetonitrile at a physiological pH of 7.4, but showed slow reactivity. This slow response was solved by addition of a surfactant, thus allowing ratiometric imaging and determination of the endogenous level of cysteine in cells in HEPES buffer, by confocal fluorescence microscopy. Imaging experiments toward various cells suggested that such aryl acrylate type probes are vulnerable to the ubiquitous esterase activity. For the selected C6 cell line, in which the esterase activity was minimal, the ratiometric quantification of cysteine level was demonstrated. The FRET probe was also applied to determine the level of cysteine in human blood plasma.

BODIPY‐Based Fluorescent Probes for Biothiols

“…The FRET probe exhibited ap romising ratiometric response to Cys, and was appliedt od etermine the level of cysteinei n living cells and human blood plasma. [87] Continuing the study of the regulation of steric hinderance of 1,7-substitution and adoptiono f4 '-methoxyphenylmercapto as the leaving group at the meso position, we successfully de-velopedC ys-selectivef luorescent probesb yi nstallation of 3,5diaryl or conformationally restricted species (55 and 56; Scheme 7). [88] In the presence of Cys, drastic changes in the ab-sorptiona nd fluorescencew ere observed for both probes.…”

A ratiometric two-photon fluorescent probe for hydrazine and its applications

“…As shown in Fig. 2, none of the tested amines (including Cysteine [14]) induced the shift of the fluorescence of TNQ except N 2 H 4 . However, N 2 H 4 induces a significant red shift of probe TNQ from 414 nm to 460 nm.…”

Benzothiazole‐Pyimidine‐Based BF2 Complex for Selective Detection of Cysteine

“…and Zhao et al. have reported a series of BODIPY derivates as fluorescent sensors for GSH ,. During our studies on the development of new BF 2 complexes, we became interested in the design of BF 2 complexes with potential applications in sensing and bioimaging of Cys, Hcy, GSH, and other amino acids.…”