A simple colorimetric sensor for the detection of moisture in organic solvents and building materials: applications in rewritable paper and fingerprint imaging

摘要

A simple off-the-shelf dye molecule, 1,4-dihydroxy-9,10-anthraquinone or quinizarin (1), has been investigated for the effective detection of moisture in organic solvents and building materials. Anion-induced deprotonation of 1 to 1.F followed by re-protonation with water is the working principle of the sensor system. Changes in colour, UV-Vis spectra and emission intensity indicate the moisture detection of 1. F in various organic solvents. The probe 1. F is more effective at the detection of water in acetonitrile and THF with a LOD of 0.0011 and 0.0026 wt%. Probe 1. F is reversible, reusable, highly selective, and sensitive and has a fast response time both in solution phase and in test papers. Probe 1. F is also applied for the detection of unknown moisture content in raw building materials such as cement, fly ash, foundry sand, and limestone. 1. F incorporated cellulose-based papers are applicable for inkless writing and stamping in the read-erase manner. Furthermore, these papers are also suitable for fingerprint imaging and sweat pore mapping by the simple colour change method.