A low-cost spray process for producing high performance CO sensors ultilzing toluene-based gold nanoparticles

This study presents a low-cost spray process for producing high performance CO (carbon monoxide) sensors utilizing toluene-based gold nanoparticles. Unlike typical metal oxide based CO sensors, the produced sensor has a good limit of detection for CO gas (<; 5 ppm) under room temperature operation. Thanks to the success synthesis of gold nanoparticles in toluene, this low surface tension solution prevents from colligation during spraying gold nano-particles on the substrate. The produced CO sensor has a good sensor linearity from 5-250 ppm (R²=0.9956). The repeatability is also confirmed by measuring a 100 ppm CO gas, the calculated variation is less than 2.8% for six repeating measurements. The method developed in this study provides a simple, reliable and low-cost method to produce high-performance Au-NPs based gas sensors.