Two-photon fluorescent chemosensors based on the GFP-chromophore for the detection of Zn2+ in biological samples – From design to application

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

“…In summary, the probe presented herein offers comparable brightness and fluorescence enhancement to our best previously reported probes while also having a more optimal wavelength for most standard laser microscopes. It is accessible via a much simpler synthesis without the need for extensive purification methods, which makes it an excellent candidate for fluorescence microscopy and two-photon imaging [18]. erol, a highly viscous solvent.…”

“…Typical Zn 2+ sensors exhibit around a 10-fold fluorescence enhancement, the two-photon absorption values are in the 700–800 nm region, and most of them emit light at around 500 nm wavelength and have binding constants in the nanomolar concentration region. 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 ].…”

“…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.…”

“…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. However, due to the challenging synthesis of the 8-aminoquinalinde building blocks required for these sensors, they are still labor-intensive to access [ 18 ]. In this work, we aimed to prepare a similarly efficient sensor that is easily accessible in a single synthetic step.…”

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

“…In this regard, and as a continuation of our interest in the design and synthesis of novel asymmetric dyes 36–42 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.…”