Some background to the problem: Recently I have measured the fluorescence spectra and found that my dye has two emission peaks. Previously I have only been using data from one peak to determine LOD and sensitivity in a standard cascade dilution assay.

Is it possible to combine the data from two peaks to improve LOD and sensitivity. Intuitively I know that if I can see both peaks at their correct wavelengths I can be confident that I have my dye present. In fact I am fairly certain it is there even when the signal is lower than 3 times the standard deviation of the background signal because it is present at both wavelengths. My question is whether there is someway to state this mathematically? Any ideas you have would be most welcome.