Na⁺ Selective Fluorescent Tools Based on Fluorescence Intensity Enhancements, Lifetime Changes, and on a Ratiometric Response.

ABSTRACT: Over the years, we developed highly selective fluorescent probes for K⁺ in water, which show K⁺ -induced fluorescence intensity enhancements, lifetime changes, or a ratiometric behavior at two emission wavelengths (cf. Scheme?1, K1-K4). In this paper, we introduce selective fluorescent probes for Na⁺ in water, which also show Na⁺ induced signal changes, which are analyzed by diverse fluorescence techniques. Initially, we synthesized the fluorescent probes 2, 4, 5, 6 and 10 for a fluorescence analysis by intensity enhancements at one wavelength by varying the Na⁺ responsive ionophore unit and the fluorophore moiety to adjust different K_d values for an intra- or extracellular Na⁺ analysis. Thus, we found that 2, 4 and 5 are Na⁺ selective fluorescent tools, which are able to measure physiologically important Na⁺ levels at wavelengths higher than 500?nm. Secondly, we developed the fluorescent probes 7 and 8 to analyze precise Na⁺ levels by fluorescence lifetime changes. Herein, only 8 (K_d =106?mm) is a capable fluorescent tool to measure Na⁺ levels in blood samples by lifetime changes. Finally, the fluorescent probe 9 was designed to show a Na⁺ induced ratiometric fluorescence behavior at two emission wavelengths. As desired, 9 (K_d =78?mm) showed a ratiometric fluorescence response towards Na⁺ ions and is a suitable tool to measure physiologically relevant Na⁺ levels by the intensity change of two emission wavelengths at 404?nm and 492?nm.

SUBMITTER: Schwarze T 

PROVIDER: S-EPMC6790620 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature