Dual mode detection of water in an organic solvent with a rhodamine-6G derivative

Abstract

A rhodamine-6G derivative was investigated as a molecular probe for qualitative and quantitative detection of water present in traces in 1,4-dioxane. The photophysical perturbations in the probe exhibiting both colorimetric (colorless ? pink color) and fluorometric(non-fluorescent ?highly fluorescent) signaling in response to presence of water content in an water-miscible organic solvents such as 1,4-dioxane. The photophysical signaling of the probe in solid state also revealed its capabilities in detection of moisture, adequately supported with TGA, DSC, FTIR and NMR spectroscopic evidences. The water induced ?off-on? signaling, the operational selectivity in medium, high sensitivity (LOD = 0.013 % v/v) and a faster response time (rate = 0.085 s-1) of the probe establishes its potential efficacy as chemosensors for water detection. The capabilities of 1 in detection of water content in 1,4-dioxane was also demonstrated in channels of a microfluidic system through colourimetric mapping of the process.