Cell permeable fluorescent receptor for detection of H2PO4− in aqueous solvent

Abstract

A new colorimetric fluorescent receptor for H₂PO₄⁻ is reported in this communication. The receptor can detect dihydrogen phosphates optically by developing a color change from yellow to green. Acute spectral responses to H₂PO₄⁻ in HEPES buffer (DMSO–HEPES 1 : 9) have been observed. The selectivity zone in terms of pH of the receptor for H₂PO₄⁻ is attributed to the fitness in the acidity (pK_a) of receptor with H₂PO₄⁻. Hydrogen bonding plays the key role here which is confirmed by ¹H NMR titration. The receptor also has good potential for bio-imaging. The mode of interaction has also been established by ab initio calculation.