SPECTRAL ANALYSES OF LOW LEVEL CHEMILUMINESCENCE OF A SHORT LIFETIME USING A HIGHLY SENSITIVE POLYCHROMATIC SPECTROMETER INCORPORATING A TWO DIMENSIONAL PHOTON-COUNTING TYPE DETECTOR

Abstract

— Spectral analyses of low level chemiluminescence were carried out by using a newly developed polychromatic spectrometer in which a diffracted photon emission was detected simultaneously using a two dimensional photon-counting device. The spectrometer was sensitive in the 400–800 nm wavelength range. Low level chemiluminescence generated in a 1 nM luminol solution could be detected as a spectrum, showing a peak at 430 nm. Short lifetime photon emission from singlet oxygen showed only two peaks at around 630 and 700 nm in this highly time-resolved spectroscopy. Lipid peroxidation of linoleic acid by the lipoxygenase emitted a low intensity peak centered at 440 nm, but singlet oxygen emission arising from the decomposition of lipid peroxide was not observed. An injured cotyledon of a soybean seedling gave a broad emission centered at 725 nm in the absence of hydrogen peroxide, while in its presence a different emission peak appeared at a shorter wavelength (515 nm). Oxygenated, fluorescent components in the soybean seedling may be the emitting species. Singlet oxygen and triplet carbonyl groups were shown to be unlikely sources of the emission.