A highly selective, colorimetric, and environment-sensitive optical potassium ion sensor. Issue 41 (19th April 2017) - Song, Guangjie
Abstract : We report a colorimetric K + sensor (KS7 ) for highly selective and accurate analysis of potassium ions. This sensor was demonstrated to be capable of analyzing potassium ions in urine with an experimental error of less than 5% using a ratiometric approach. Further, K + test strips can be easily prepared, which were used to detect K + in urine conveniently for daily health monitoring. Abstract : Potassium ions (K + ) play vital roles in many biological processes and thus highly selective sensors for K + are critical for disease diagnosis and health monitoring. Herein, we report a colorimetric K + sensor (KS7 ) in which a hemicyanine dye was used as a fluorophore and phenylaza-[18]crown-6 lariat ether (ACLE) was utilized as a K + ligand. The maximum absorption peak ofKS7 shifted hypsochromically by 77 nm (from 515 to 438 nm) with an isosbestic point at 452 nm upon the addition of K + to its aqueous solution accompanied by a color change from red to yellow. This sensor exhibited a linear response range to K + from 1 to 200 mM, indicating its wide detection range for cellular, urinary, and environmental potassium ions. Further, this sensor is solvent-sensitive, implying its environmental sensitivity. For the demonstration of its applications, we prepared filter paper-based K + test strips, which were used to detect K + in urine conveniently.