A Fluorescent Ratiometric Potassium Sensor Based on IPG4-Silica Microparticles for Selective Detection and Fluorescence Imaging of Potassium Cations

TL;DR

This paper introduces a novel silica-based fluorescent microsensor for potassium detection, enabling selective, non-toxic, and in situ imaging of K+ ions in biological systems with high sensitivity.

Contribution

The study presents a new ratiometric fluorescent microsensor using silica microparticles and ION potassium green 4 for selective potassium detection and imaging.

Findings

Microsensors have a sensitivity range of 0-40 mM for K+.

The sensors are spherical, monodisperse, and non-toxic in cell cultures.

They enable fluorescence imaging of potassium in biological environments.

Abstract

Potassium cations play many important roles in living organisms, especially in electro-physiology, since they are involved in neurotransmission and muscle contractions. We report the synthesis of a ratiometric fluorescent microsensor for potassium (K+) detection, based on the fluorescent probe ION potassium green 4. Potassium-sensitive fluorescent microparticles were obtained by using silica as core material. We obtained silica-based microsensors with a size in the micrometer range, spherical shape, good monodispersity, optimal selectivity and a sensitivity range between 0 to 40 mM. The microsensors also proved to be non-toxic in cell cultures as well as suitable for fluorescent imaging, offering new possibilities for non-invasive optical detection, quantification and in situ monitoring of K+ variations in cell culture systems.