1. Department of Chemistry; University of Turku; Vatselankatu 2 20014 Turku Finland
2. Department of Biochemistry/Biotechnology; University of Turku; Tykistökatu 6 A 20520 Turku Finland
3. BAM Federal Institute for Materials Research and Testing; Division 1.10: Biophotonics; Richard-Willstätter-Str. 11 12489 Berlin Germany