Fast recognition of trace volatile compounds with a nanoporous dyes-based colorimetric sensor array.

Volatile compounds (VCs) are almost harmful to health even at low concentrations and can be used as potential biomarkers to indicate the risk of diseases. Here we report a new "nanoporous pigment array" constructed with composites of chemically responsive dyes and four nanomaterials that were successfully prepared with expected properties for rapid and highly portable identification of trace VCs. Using the array, clear differentiation has been easily achieved for 16 common VCs at low ppm concentrations within four minutes through the distinguishable difference maps. Based on the pattern recognition of HCA, PCA and LDA, five parallel samples of each VC could be classified accurately with an accuracy of ≥ 91.2%. Additionally, the nanoporous pigment array shows modest stability against the changes in humidity or temperature over a wide range, excellent batch to batch reproducibility and a long shelf life. Compared to current colorimetric sensor arrays only based on diverse chemo-responsive dyes, the improved reactivity of the nanoporous pigment implies that the functionalization with particular nanomaterials is one of most promising paths to further improving the properties of arrays. Generally, the "nanoporous pigment array" presents excellent properties for fast identification of VCs.