Fluoresceinyl Cypridina Luciferin Analog (FCLA) is a chemiluminescence (CL) probe for detecting reactive oxygen species (ROS). Its detection efficiency of singlet oxygen can be significantly enhanced in the presence of human serum albumin (HSA). In the current study, the mechanism of the FCLA-HSA CL system is studied by means of direct CL measurement and spectroscopy techniques. Our results show that FCLA can combine with HSA via a single binding site to form a complex. The CL efficiency of the system is largely governed by an inter-system energy transfer between the two components upon interaction with singlet oxygen. The CL production reaches maximum in a synergetic manner when equal amount of FCLA and HSA are present simultaneously, but the production is less efficient at other ratios. This suggests that the FCLA-HSA system maybe used as a singlet oxygen detecting technique with higher sensitivity compared with that of conventional CL techniques. It may also provide a potential new technique for quantitatively analyze the presence of HSA in a sample.

Date Published: 6 March 2006
PDF: 11 pages
Proc. SPIE 6139, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XV, 61390U (6 March 2006); doi: 10.1117/12.643602

Published in SPIE Proceedings Vol. 6139:
Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XV
David Kessel, Editor(s)