Naphthalenetetracarboxylic diimide derivatives (octyl “8” NTCDI, dimethylaminopropyl “DMP” NTCDI) and copper phthalocyanine (CuPc) are used to form a diverse organic field-effect transistor (OFET) sensor array. CuPc and 8-NTCDI are p-channel and n-channel semiconductors, respectively, showing expected and opposing responses to analytes. DMP-NTCDI, on the other hand, because of its ionizable side chain, shows response directions and magnitudes that are not correlated to those of the other two. The result is a distinct response pattern and unambiguous recognition ability for individual analytes. The differences are even more dramatic if the time evolution of the responses is considered. The three-response patterns obtained from representative polar, nonpolar, acidic, and basic vapors are all different, showing the potential for this approach in rapid, low-cost electronic detection of volatile compounds.