Detection of Mixed BTEX With Suppressed Reaction Specificity Using Tin Oxide Nanoparticles Functionalized by Multi-Metalloporphyrins

Typical BTEX sensors that exhibit different response for individual BTEX were difficult to accurately measure the amount of mixed BTEX with an arbitrary ratio and thus a calibration was required for accurate concentration measurement. Herein we demonstrated a BTEX (benzene, toluene, ethylbenzene, and xylene) sensor using tin oxide nanoparticles (SnO2 NPs) functionalized by multi-metalloporphyrin (MMPP) as sensing materials. The SnO2 NP/MMPP-based BTEX sensor platform was fabricated by using scalable processes based on micromachining technology and solution-based SnO2 NPs/MMPP deposition. Our SnO2 NP/MMPP-based BTEX sensor exhibits suppressed response specificity for individual BTEX, unlike the previously studied BTEX sensors which exhibited different responses to each gas. Therefore, the BTEX sensor does not need parameters such as 'response factor' or 'correlation factor' to calibrate. Moreover, the amount of mixed BTEX gas with an arbitrary concentration ratio can be detected with a small response error. The BTEX sensors also showed reliable responses with an error of less than 9% at the same concentration for each BTEX compound and mixed BTEX.