Lead ion detection using glutathione-functionalized aluminum gallium nitride/gallium nitride high-electron-mobility transistors

Abstract

This work presents a new approach for lead ion detection (Pb2+) using an aluminum gallium nitride/gallium nitride (AlGaN/GaN) high-electron-mobility transistor (HEMT) sensor. The AlGaN/GaN HEMT structure of the sensor was realized by functionalizing the gate area with glutathione (GSH). The crystalline and surface qualities of the AlGaN film were measured through X-ray diffraction and atomic force microscopy. The response of the sensor was measured in terms of the source–drain current with varying concentrations of Pb2+ ions at a fixed drain-to-source voltage. The sensitivity of the sensor was 29.3 μA/(mg/L), and it exhibited high selectivity toward Pb2+. The results show that using the GSH-functionalized AlGaN/GaN HEMT sensor is a promising strategy for Pb2+ ion detection.