Light‐Addressable Potentiometric Sensor with Nitrogen‐Incorporated Ceramic Sm2O3 Membrane for Chloride Ions Detection

Abstract

A light‐addressable potentiometric sensor (LAPS) with ceramic samarium oxide (Sm2O3)‐sensing membrane treated by nitrogen plasma immersion ion implantation (PIII) has been proposed for chloride ion detection. For the pure Sm2O3‐LAPS, a potassium ion sensitivity of 39.21 mV/pK is obtained. With the nitrogen PIII treatment on Sm2O3‐sensing membrane, the N–O peak is observed by X‐ray photoelectron spectroscopy, implying the formation of positive charges, (N‐O)+ and (N‐O‐N)+, within the Sm2O3 film. The positive charges can attract the chloride ions to react with the surface sites of OH2+, achieving a superior chloride ion sensitivity of 36.17 mV/pCl for the Sm2O3‐LAPS with nitrogen PIII treatment. The LAPS structure with ceramic Sm2O3‐sensing membrane can be used for future biosensing applications, especially for the potassium and chloride ions detection in serum.