  The autofluorescence of calabrian Opuntia ficus-indica bioactive extract upon
UV illumination is explored by fluorescence spectroscopy enabling to
investigate the typology and distribution of responsible molecules within green
cladodes. The spectroscopic analysis of the extract shows a significative red
emission, suggesting an abundance of chlorophylls in the sample. Such molecules
show pronounced fluorescence in the visible range (400-800 nm) with a very
large Stokes shift, when excited with UV light source. The fluorescence
profiling is performed also in the case of polymers, such as poly(methyl
methacrylate) (PMMA), poly(vinylpyrrolidone) (PVP) and polyvinyl alcohol (PVA),
enriched with OFI extract with a signal improvement up to 40 times greater than
the extract alone. This by-product fluorescent molecule can replace commercial
dyes into several applications spanning from nano-optics to anti-counterfeiting
and bioimaging.
