Detection of Moisture by Fluorescent OFF-ON Sensor in Organic Solvents and Raw Food Products.

Copper complex based on a new class of fluorescence OFF-ON sensor 1.Cu has been reported for the detection of trace amounts of water in various organic solvents such as CH3OH, THF, CH3CN, and acetone by means of fluorescence emission intensity. The probe is highly responsive to water in THF (DL = 0.003 wt %). The dissociation of copper from probe 1.Cu in the presence of water is responsible for the fluorescence change and it was confirmed by electrospray ionization-mass spectrometry (ESI-MS), proton nuclear magnetic resonance (1H-NMR), and fluorescence lifetime studies. Real application of the probe was successfully applied for the detection of moisture content in commercial products such as salt, sugar, wheat, and washing powder.