Calcein blue—a new metalfluorechromic indicator for chelatometric titrations

High-performance liquid chromatography method for ferric iron chelators using a post-column reaction with Calcein Blue

“…These results are consistent with the formation of a 1:1 CB-Fe(III) complex [27] and consequent quenching of CB fluorescence. Other metal ions such as Cu(II), Mn, Ni, Co(II), Pd, and Fe(II) have also been shown to quench the fluorescence of CB [28][29][30]. Our results indicate that Fe(III) also quenches the fluorescence of CB.…”

Identification of the first small-molecule ligand of the neuronal receptor sortilin and structure determination of the receptor–ligand complex

“…1b) and could thus potentially cause assay interference by fluorescence. Furthermore, molecules of the general type 1 have been reported (Wilkins, 1960) to ligate metals via a tridentate binding interaction (compound 2; Fig. 1b), which could also potentially cause assay interference.…”

Photoaktivierungsfähige Rhodamine als Bio-Calcium-Sensoren und Markierungen für Tetracystein-Tags in Proteinen

“…Coumarin-based analytical indicators for calcium. [25,26,28] The properties of the coumarin derivatives 2c, 2d were reported by Huitink [26] in greater details than the of Calcein Blue. The working principles of indicators 2c and 2d are the same as for compound 2b.…”

“…Due to its brilliant blue fluorescence, this compound was called Calcein Blue. [25] In the absence of calcium, aqueous solutions of this substance are intensively fluorescent only at pH 11, but even at pH = 12, the solutions become fluorescent again, if a calcium salt is added. Unfortunately, in the original publication the synthesis was not reported, but some spectral data were given: the maxima of absorption ( (acidic solution) = 330 nm, (basic solution) = 370 nm) and fluorescence ( = 445 nm).…”