achieved with no errors or misclassifications. Especially for weakly
responding VOCs, the sensor array showed its excellent discrimination capability. The limit of detections of the electronic nose for 14 VOCs were extrapolated, and most of them were below their PEL levels. We expect that this method will expand the application of SMO sensor array-based electronic nose which have been largely limited by the selection of commercially available SMOs and dopants. Further instrumentation and miniaturization is under development in our lab. The preparation technique conditions, such as distribution of sensing materials, surface roughness of substrates,etc., will be paid more attention in order to obtain better reproducibility. Acknowledgements We thank Dr. Christopher J. Musto for his useful discussion and revision of the manuscript. The work was supported through the National Natural Science Foundation of China (grant no. 21177125, 21021004) and the 100 talents program which is funded by Chinese Academy of Sciences. Appendix A. Supplementary Information Supplementary data associated with this article can be found in the online version athttp://dx.doi.org/10.1016/j.bios.2014.09.081.