An Electronic Nose Transducer Array of Vapoluminescent Platinum(II) Double Salts

The development of environmental sensors continues to be an active area of research especially the development of a practical 'electronic nose." Gardner and Bartlett define an electronic nose as "an instrument which comprises an array of electronic chemical sensors with partial specificity and an appropriate pattern recognition system, capable of recognizing simple or complex odors." The chemistry associated with detection and signal transduction is of central importance in these types of devices. Electronic nose transducers reported to date include: semiconducting metal oxides, conducting polymer films, acoustic wave devices, field-effect transistors, electrochemical sensors, pellistors, carbon-black loaded polymer film chemoresistors, and conductometric sensors based on electrolyte/polymer composites. Recent reports describe optical transducers with immobilized dyes such as Nile Red or various metalloporphyrins. Surface-modified semiconductor materials also show great promise as photoluminescent transducers for gas sensing. In general, many optical transducers depend as much on vapor/matrix interactions as on vapor/chromophore interactions for their discriminating power. Changes induced in the matrix/chromophore ensemble by the vapor are detected as a spectroscopic response of the chromophore that is usually analyzed by a multivariate statistical technique to identify analyte vapors.