Methods and sensors for the detection, identification, and quantification of one or more gas species, including volatile organic compounds, in a test sample are described. Methods employ gas sensors comprising a diffusion matrix present on the sensor surface. A gas analyte in a test sample diffuses through the matrix and is detected upon interaction of the analyte with the sensor. A response profile of a gas sensor to a gas analyte in the test sample is compared to a control gas sensor response profile determined in a similar manner for a known gas species. Comparisons of test sample and control sample sensor response profiles enable detection, identification, and quantification of a gas species analyte in a test sample.