A method combining laser-induced fluorescence and principal component analysis to detect and discriminate between algal and fungal growth on insulator materials has been studied. Eight fungal cultures and four insulator materials have been analyzed. Multivariate classifications were utilized to characterize the insulator material, and fungal growth could readily be distinguished from a clean surface. The results of the principal component analyses make it possible to distinguish between algae infected, fungi infected, and clean silicone rubber materials. The experiments were performed in the laboratory using a fiber-optic fluorosensor that consisted of a nitrogen laser and an optical multi-channel analyzer system.
M. Bengtsson, S. Wallström, M. Sjöholm, R. Grönlund, B. Anderson, A. Larsson, S. Karlsson, S. Kröll, and S. Svanberg, "Fungus Covered Insulator Materials Studied with Laser-Induced Fluorescence and Principal Component Analysis," Appl. Spectrosc. 59, 1037-1041 (2005)