A red-emitting ratiometric fluorescent probe based on a benzophosphole P-oxide scaffold for the detection of intracellular sodium ions

Abstract

We disclose the development of a ratiometric fluorescent probe based on a benzophosphole P-oxide and its application for the detection of intracellular Na(+) ions. Excitation by visible light induced red emission from this probe in water, which was subjected to a hypsochromic shift upon complexation with Na(+). Based on this change, a ratiometric analysis enabled us to visualise changes in the Na(+) concentration in living mammalian cells.

Highly selective chromoionophores for ratiometric Na+sensing based on an oligoethyleneglycol bridged bithiophene detection unit

“…On average, sensors S1-S9 displayed a 68-fold, 13-fold and 21-fold stronger response towards Na + compared to Li + , K + and Ca 2+ respectively, indicating excellent analyte selectivity and comparable to those of other Na + ion selective ratiometric optical probes. [16][17][18][19] The varying degrees of contrast between sensors S1-S9 in their Na + free and bound form (20-70%) can be attributed to their different dissociation constants (Kd). These in turn were obtained from the Benesi-Hildebrand plot of each sensor (see Figures S55-S63 in the supporting information).…”

“…Despite the numerous Na + optical probes that have been developed over the past decades, only a handful of these display ratiometric sensing behaviour. [16][17][18][19] One frequently encountered drawback of the currently available ratiometric Na + colorimetric sensors is their absorption predominantly in the UV-region, leading to low tissue penetration and phototoxic damage in biological specimens. Another disadvantage of their absorption profiles in the short wavelength region is the requirement to evaluate their optical and ion-binding properties employing spectrophotometers.…”

Organophosphorus Compounds in Organic Electronics

“…Complexation with sodium ions 18 (Na + ) also shifts the emission band towards shorter wavelength ( λ em =620 nm) concomitantly with an increase in quantum yield to Φ =0.028. Except for almost negligible effects on K + , the insensitivity of emission towards calcium, magnesium, and other trace metals ions makes this system a useful sodium sensor in physiological relevant conditions . Another sensor application of phosphole 19 (Figure ) was demonstrated by the Baumgartner group, who introduced a cyclodextrin moiety to the phosphole core by means of a click reaction.…”

“…Except for almostn egligible effects on K + ,t he insensitivity of emission towards calcium, magnesium, and other trace metalsi ons makes this system au seful sodium sensor in physiological relevantc onditions. [57] Another sensor application of phosphole 19 (Figure 4) was demonstrated by the Baumgartner group, who introduced ac yclodextrin moiety to the phosphole core by meanso faclick reaction. This novel system showed fluorescenceq uenching by the nitroaromatic explosive picric acid in aqueous solutions.…”

Phosphole <i>P</i>-Oxide-Containing π-Electron Materials: Synthesis and Applications in Fluorescence Imaging

“…28 Sodium ions play essential roles in the regulation of signal transactions. Although several commercially available uorescent sodium ion probes, such as SBFI and CoroNa Green, have been widely employed, these probes still suffer from certain drawbacks in terms of e.g.…”