Polychromatic fingerprinting of excitation emission matrices

The ability of a ubiquitous polychromatic excitation to support the fingerprinting of the Excitation Emission Matrices (EEM) of fluorescent indicators was reported. Solutions of fluorescent molecules, with concentration of 2μM for the absorption and 10μM for the emission measurements were prepared. Spectroscopic grade THF and distilled water passed through Milli-Q purification system were used as solvents. EEM measurements were carried out on a spectrofluorimeter, operating in the 390-700 nm detection range, with excitations at 20 nm intervals within the same range. During the measurement, the screen displayed a sequence of 50 colors and for every color, the transmission and emission spectrum of both the reference and the sample were recorded. Illuminating colors in the red region are not able to excite fluorescence and this can be seen in the spectra for red light.