Fig. 5From: Fabrication and characterization of VOC sensor array based on SnO2 and ZnO nanoparticles functionalized by metalloporphyrinsConcentration-response graphs of the sensor array composed of 4 MOX NP/MPP-based sensors for BTEX. a SnO2/CoPP, b SnO2/ZnPP, c SnO2/NiPP, and d ZnO/CoPPBack to article page