Synthesis and Application of Two-Photon Active Fluorescent Rhodol Dyes for Antibody Conjugation and In Vitro Cell Imaging

Abstract

A novel family of julolidine-containing fluorescent rhodols equipped with a wide variety of substituents was synthesized in a versatile two-step process. The prepared compounds were fully characterized and exhibited excellent fluorescence properties for microscopy imaging. The best candidate was conjugated to the therapeutic antibody trastuzumab through a copper-free strain-promoted azide-alkyne click reaction. The rhodol-labeled antibody was successfully applied for in vitro confocal and two-photon microscopy imaging of Her2+ cells.

A Molecular Hybrid of the GFP Chromophore and 2,2′-Bipyridine: An Accessible Sensor for Zn2+ Detection with Fluorescence Microscopy

“…They have a few practical limitations, such as their solubility or selectivity [ 18 ]. In light of these aspects, as a continuation of our interest in novel fluorescent dyes and two-photon active compounds [ 19 , 20 , 21 ], we aimed to develop a novel family of two-photon sensors for Zn 2+ by modifying the Green Fluorescent Protein (GFP) chromophore with a built-in 8-aminoquinoline motif, which made the probe Zn 2+ -sensitive [ 18 ]. The novel family, named GFZnP, exhibited excellent two-photon properties, its use was demonstrated in biological experiments, and it overcame the practical limitations of other sensors.…”

Effective synthesis, development and application of a highly fluorescent cyanine dye for antibody conjugation and microscopy imaging

“…[30][31][32][33][34][35] In this regard, and as a continuation of our interest in the design and synthesis of novel asymmetric dyes [36][37][38][39][40][41][42] and antibody modification, we herein describe the development of a novel fluorescent cyanine dye. 37,43,44 The strengths of our novel asymmetric cyanine are as follows: first, we increased solubility by introducing a positively charged ionic core; second, we improved its photophysical properties, in particular increasing the Stokes shift by 25 nm, which improved image quality and reduced self-absorption, achieving an excitation maximum at the desirable 633 nm wavelength, and an improving photostability; and third, we added an azide-containing linker that enables its application in azide-alkyne click reactions, which results in an optimal fluorophore-antibody ratio. Thereafter we successfully cross-linked the candidate dye to the therapeutic antibody trastuzumab.…”