Solvatochromism as a tool to visually recognise wide range of commonly used solvents and inexpensive dye based optical sensor for H2O, D2O and H2O2

Abstract

An inexpensive bisphenol based optical sensor (BP) obtained from single step reaction of 4-hydroxybenzyladehyde and 2,6-dimethyl phenol was designed and subsequently synthesized. BP effectively recognize wide range of commonly used solvents through solvatochromism. The recognition technique of the solvents was also extended to computer application detection. Induced deprotonation enhanced the activity of sensor enabling detection of water and heavy water content in organic solvents up to 1.57 × 10-8 M and 2.64 × 10-8 M respectively as well as qualitatively distinguishing water from its heavy form. The BP effectively detect H2O2 colorometrically with LOD of 1.86 × 10-6 M and the efficiency of H2O2 detection was significantly improved through induced deprotonation of BP. Colorimetric and flurometric H2O2 detection of deprotonated form of BP (DBP) were also demonstrated. BP as well as DBP selectively detect H2O2 over other peroxides namely benzoyl peroxide and tert-butyl hydro peroxide. Then, BP was effectively immobilized in hydrogel matrix for solid state detection of H2O2 in purely aqueous system through induced deprotonation of immobilized BP with base namely F-/CN– ion. The hydrogel composite film exhibit significant stability to various environmental conditions.