Fig. 14.

(a) Normalized fluorescence emissions captured by the SFE between 500 and 540 nm after excitation at 442 nm. The star shape is a FL-in-polymer dye target with a concentration of 1 μM, whereas the background fluorescence is due to the embedded collagen AF. Image analysis shows the target-to-background signal ratio was 4:1. (b) Comparison of AF emissions shows that the phantom fluorescence emission is similar to that of pure collagen. A spectrometer was used to test the excitation fiber to address concerns that it may exhibit autoflouresence (USB2000+, Ocean Optics, Inc.). No autofluorescence signal was detected with the laser excitation power used in the current study.