A portable optoelectronic nose for the identification of explosives uses a highly cross-reactive colorimetric sensor array and a handheld scanner.

A colorimetric sensor array has been designed for the identification of and discrimination among aldehydes and ketones in vapor phase. Due to rapid chemical reactions between the solid-state sensor elements and gaseous analytes, distinct color difference patterns were produced and digitally imaged for chemometric analysis. The sensor array was developed from classical spot tests using aniline and phenylhydrazine dyes that enable molecular recognition of a wide variety of aliphatic or aromatic aldehydes and ketones, as demonstrated by hierarchical cluster, principal component, and support vector machine analyses. The aldehyde/ketone-specific sensors were further employed for differentiation among and identification of ten liquor samples (whiskies, brandy, vodka) and ethanol controls, showing its potential applications in the beverage industry.

Sensitive detection of trimethylamine both in aqueous and gaseous phases has been accomplished using an inexpensive colorimetric sensor array. Distinctive color change patterns provide facile discrimination over a wide range of concentrations for trimethylamine with >99% accuracy of classification. Calculated limits of detection are well below the diagnostically significant concentration for trimethylaminuria (fish malodor syndrome). The sensor array shows good reversibility after multiple uses and is able to cleanly discriminate trimethylamine from similar amine odorants. Portable sensing of trimethylamine vapors at ppb concentrations is described using a cell phone camera or a hand-held optoelectronic nose. Application of the sensor array in detecting mouth and skin odor as a potential tool for portable diagnosis of trimethylaminuria is also illustrated.

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Ac olorimetric sensor arrayh as been designed for the identification of and discrimination among aldehydes and ketones in vapor phase.D ue to rapid chemical reactions between the solid-state sensor elements and gaseous analytes, distinct color difference patterns were produced and digitally imaged for chemometric analysis.T he sensor arrayw as developed from classical spot tests using aniline and phenylhydrazine dyes that enable molecular recognition of aw ide variety of aliphatic or aromatic aldehydes and ketones,a s demonstrated by hierarchicalc luster,p rincipal component, and support vector machine analyses.T he aldehyde/ketonespecific sensors were further employed for differentiation among and identification of ten liquor samples (whiskies, brandy,v odka) and ethanol controls,s howing its potential applications in the beverage industry.