Cancellation of Contact Quenching : A Simple Concept for Selective Chemosensing of Basic Fluoride and Acetate Anions

A weakly fluorescent acid-base pair formed by reacting fluorescent acridine orange with the quencher picric acid is reported for the detection of basic fluoride and acetate anions. Deprotonation by these anions causes disengagement of the fluorescent acridine orange from the quencher, picric acid. This phenomenon cancels the quenching existing in the native probe, thereby allowing for the optical signalling of fluoride and acetate anions by color modulation as well fluorescence switch-on response. Anions such as Br-, I-, Cl-, NO3-, SCN-, HSO4-, and H2PO4- offer no detectable interferences even in excess concentrations

Cancellation of contact quenching: A simple concept for selective chemosensing of basic fluoride and acetate anions

1164-1168A weakly fluorescent acid-base pair formed by reacting fluorescent acridine orange with the quencher picric acid is reported for the detection of basic fluoride and acetate anions. Deprotonation by these anions causes disengagement of the fluorescent acridine orange from the quencher, picric acid. This phenomenon cancels the quenching existing in the native probe, thereby allowing for the optical signalling of fluoride and acetate anions by colour modulation as well as fluorescence switch-on response. Anions such as Br, I, Cl, NO3, SCN, HSO4, and H2PO4 offer no detectable interference even when in excess concentration

A simple and efficient dual optical signaling chemodosimeter for toxic Hg(II)

10-Methylthioacridone, designated as acrithion, has been employed as an easily accessible chemodosimeter for the optical targeting of toxic Hg2+ in buffered aqueous DMSO. The Hg2+-mediated desulfurization of the probe is translated into selective dual signaling of Hg2+ by means of color bleaching and fluorescence amplification while several other metal ions, including potentially competing Ag+, Cu2+ and Pb2+, afford no significant interferences even in excess concentrations