“Alive” dyes as fluorescent sensors: fluorophore, mechanism, receptor and images in living cells

Abstract

In this feature article, we report our recent progresses in fluorescent sensors of biological dyes from the viewpoint of supramolecular and bioorganic chemistry. For signalling fluorophores, we extended or created naphthalene-based ICT systems, e.g. amino-1,8-naphthalimides, amino-1,8-dicyanonaphthalenes and acenaphthopyrrol-9-carbonitriles. We also developed BODIPY derivatives with large Stokes shifts and high fluorescence quantum yields in polar solvents, and a rhodamine analogue working in strong competitive aqueous solution as well as its silaanthracene analogue with a bathochromic shift as large as 90 nm. For sensing mechanisms, we extended or developed the following methods to improve sensing: e.g. PET in a photogenerated electronic field, TICT promoted PET derived from aminoalkyl or piperazino aminonaphthalimides, and the translation/amplification effect of surfactant micelles or aggregation on fluorescent sensing. We also successfully designed deprotonation strengthened ICT, FRET-chemodosimeter sensing systems. For non-cyclic recognition receptors, naphthalimides with two or more side chains at their 4,5- or 3,4-positions, as a convenient and simple platform for ratiometric sensors, were created for the recognition of heavy and transition metallic cations; multi-armed polyamides with more side chains were innovated as a versatile platform for the sensing of metal ions with high affinity, selectivity and positive homotropic allosteric effects. We designed V-shape sensors of the bis(aminomethyl)pyridine receptor with two fluorophores to show high performance. Finally, the intracellular applications of the above sensors and dyes, e.g. imaging heavy and transition metal ions in cells, fluorescent marking of hypoxia of tumour cells, are also reviewed.

Intramolecular charge transfer and sensing mechanism for a colorimetric fluoride sensor based on 1,8-naphthalimide derivatives

“…From the viewpoint of analytical science, a dye's light emission is much more sensitive than its light absorption [35]. As previously reported, the chemosensors based on 4-amino-1,8-naphthalimides are usually typical fluorophores with an ICT character [35], and most of them can be a good candidate for fluorescent chemosensor [1,35].…”

“…As previously reported, the chemosensors based on 4-amino-1,8-naphthalimides are usually typical fluorophores with an ICT character [35], and most of them can be a good candidate for fluorescent chemosensor [1,35]. Hence, in this section, we shall investigate the emission characters of the chemosensor TBS-NA to verify its potential as a fluorescent chemosensor for fluoride anion.…”

Mapping of Heavy Metal Ion Sorption to Cell-Extracellular Polymeric Substance-Mineral Aggregates by Using Metal-Selective Fluorescent Probes and Confocal Laser Scanning Microscopy

“…More than 1,000 different small organic molecule-based metal fluorescent probes have been described since 1997 that allow for quantitative analysis of dissolved metal concentrations and microscopic metal localization in biological samples in combination with CLSM (32)(33)(34)(35). However, this has been applied almost exclusively in the field of cell biology.…”

Building pH Sensors into Paper-Based Small-Molecular Logic Systems for Very Simple Detection of Edges of Objects

“…Following our discovery of the fluorescent PET sensing capabilities of the 4-(aminoalkyl)-aminonaphthalimide system, 48 it was developed into metal sensing applications by Roche Diagnostics in consultation with us 49,50 and it was also taken up by many others. 39,[51][52][53][54][55] So it is natural that many of us would continue to exploit the useful properties of this molecular motif: hence, our use of sensors 1 and 4 in the current work. A simple logic step is insufficient to go from ref.…”