A sandwich device was prepared by electrodeposition of an insoluble layer
of oligomerized tris(4-(2-thienyl)phenyl)amine onto conducting indium-tin
oxide coated glass, spin coating the stacked platinum compound,
tetrakis(p-decylphenylisocyano)platinum tetranitroplatinate, from toluene
onto the oligomer layer, and then coating the platinum complex with
aluminum by vapor deposition. This device showed rectification of current
and gave electroluminescence. The electroluminescence spectrum
(.mu..sub.max =545 nm) corresponded to the photoluminescence spectrum of
the platinum complex. Exposure of the device to acetone vapor caused the
electroemission to shift to 575 nm. Exposure to toluene vapor caused a
return to the original spectrum. These results demonstrate a new type of
sensor that reports the arrival of organic vapors with an
electroluminescent signal. The sensor comprises (a) a first electrode; (b)
a hole transport layer formed on the first electrode; (c) a
sensing/emitting layer formed on the hole transport layer, the
sensing/emitting layer comprising a material that changes color upon
exposure to the analyte vapors; (d) an electron conductor layer formed on
the sensing layer; and (e) a second electrode formed on the electron
conductor layer. The hole transport layer emits light at a shorter
wavelength than the sensing/emitting layer and at least the first
electrode comprises an optically transparent material.