A Water-Soluble, Small Molecular Fluorescent Sensor with Femtomolar Sensitivity for Zinc Ion

Abstract

A water-soluble fluorescent sensor, 1, based on the quinoline platform, demonstrates femtomolar sensitivity for zinc ion with a 14-fold enhanced quantum yield upon chelation to zinc ion and also exhibits high selectivity to zinc ion over other physiological relevant divalent metals in the presence of EDTA. X-ray crystal structure of zinc complex reveals that an acetic carboxylic group participates in coordination, which significantly enhances the affinity of 1 for zinc ion.

Ternary complex formation and competition quench fluorescence of ZnAF family zinc sensors

“…Nearly all are unable to saturate the Zn 2+ coordination sphere completely, with one possible exception of a novel sensor characterized by NMR and X-ray studies to be 6-coordinate in a rare geometry of pentagonal pyramid. 5,43 Table 2 The prediction of the effect of physiological concentrations of LMWLs on the fluorescence of ZnAF-1 and ZnAF-2F; components of the LMWL mixture used in the experiment illustrated in Fig. 4 We demonstrated that all these compounds quench the sensors' response, leading to a significant underestimation of Zn(II) concentrations in vitro.…”

Fluorescent chemosensors for Zn2+

“…10). 37 Compound 27 is water-soluble with a 14-fold enhanced quantum yield upon chelation to zinc ion (l ex = 315 nm; l em = 435 nm). NMR studies and the crystal structure of 27-Zn 2+ complex indicate that the oxygens at the 8 position (O1) and the carboxylic group (O2) participate in the chelation of the zinc ion along with the quinoline nitrogen atom (N1) and DPA (N2-N4) to endow 27 with a high binding affinity (K d = 0.45 pM).…”

1,8-Naphthyridine and 8-hydroxyquinoline modified Rhodamine B derivatives: “Turn-on” fluorescent and colorimetric sensors for Al3+ and Cu2+

“…The chemosensors were synthesized according to the route as shown in Scheme 1 and modified methods [33,48,49]. …”