A. PELED^#, SIMONA ALEXANDRA POPESCU

Photonics Laboratory, Holon Institute of Technology, 52 Golomb Str., Holon, 5867910, Israel

This study examined the absorption and fluorescence spectra of chlorophylls and other pigments extracted in ethanol solutions from common edible plant species. Chlorophyll-a was the dominant fluorescent chromophore in all plant varieties. The fluorescence curves for all extracted solutions exhibit after optimizing by concentration dilution an increase in the fluorescence with a typical prominent leading Gaussian peak at a wavelength of 674 nm. This peak is followed by a decreasing shoulder extending into the near-infrared range beyond 724 nm. The dilution of the solutions with ethanol reduces the optical absorption from the other pigments and shows simultaneously an improved resolution of the chlorophyll-a spectral absorption peaks. This investigation provides new insights into the optical absorbance and other photo-excited processes that impact the fluorescence of chlorophylls, such as agglomeration, photobleaching and photo-aggregation. The findings may be used for bio- diagnostics, fluorescent quantum dots and bio-sensors.

Key words: Chlorophyll, spectral analysis, intrinsic fluorescence

Corresponding author’s e-mail: peled@hit.ac.il