A Ratiometric Green to Blue Emitting Hg2+ Ions Responsive Ionic Liquids-based Micro-optode

Abstract

This work presents a Hg2+ ions responsive ratiometric green-to-blue-emitting ionic liquids (ILs), trihexyltetradecylphosphonium hydroxyproline-1, 3, 6-trisulfonate (HPTIL) and its micro-optode, mHPTIL. Neat HPTIL functions as photoluminescence ink without a solvent, highlighting its effectiveness as a safekeeping script material and displaying green-to-blue-emitting Hg2+ ions responsive photoluminescent ILs. Upon the introduction of heavy metal, Hg2+ ion, into the system solution water-suspended mHPTIL, a noticeable ratiometric shift from greenish to bluish fluorescence was observed, having detection and quantification limits in the nanomolar (nM) range with the lowest LOD of 1.67 nM. Additionally, a very convenient and portable solid-state paper-strip-based test kit has been introduced fabrication to monitor heavy metal, Hg2+ ion. This work proposes a novel approach to generating low-dimensional materials based on ILs that have exceptional qualities for environmental and forensic monitoring.