An ionophore-based persistent luminescent ‘Glow Sensor’ for sodium detection

Abstract

sensors. Persistent luminescence readouts can avoid cellular autofluorescence during biological monitoring, leading to an improved signal-to-noise ratio over a more traditional fluorescence readout. In this study, we show for the first time an ionophore-based optical bulk optode sensor that utilizes persistent luminescence microparticles for ion detection. To achieve this, we combined long-lifetime strontium aluminate-based 'glow-in-the-dark' microparticles with a non-fluorescent pH-responsive dye in a hydrophobic plasticized polymer membrane along with traditional ionophore-based optical sensor components to create a phosphorescent 'Glow Sensor'. The non-fluorescent pH indicator dye gates the strontium aluminate luminescence signal so that it decreases in magnitude with increasing sodium concentration. We characterized the Glow Sensor in terms of emission lifetime, dynamic range, response time, reversibility, selectivity, and stability.