A rhodamine based “off-on” probe for selective detection of Hg(ii) and subsequent l-proline and 4-hydroxyproline discrimination

Abstract

A substituted rhodamine based bifunctional chemosensor 2 showed “turn-on” chromogenic and fluorogenic dual mode signal modulation upon selective binding with Hg(II) whereas its Hg(II) complex selectively detects L-proline among all biologically significant amino acids by quenching of its enhanced fluorescence. In the process of ‘Off-On-Off’ signaling, the complex therefore discriminates L-proline and its hydroxyl derivative, which is a vital phenomenon of inducing selectivity among amino acid identification.