With a view to assessing the current boundaries of non-invasive sensing of metabolites we compare the photophysical properties of melanin nanoparticles in vivo, size selected in natural form from Sepia officinalis extracted from cuttlefish, and synthesised from L-dihydoxyphenylalanine (DOPA) in water pools of reverse micelles. The fluorescence emission spectra and excited state decay components correlate well with the particle size. Recent developments in optical technology are discussed in the context of the formidable challenges and opportunities for metabolic sensing presented by endogenous fluorophores.
- self-organisation in macromolecules
- optical absorption
- emission spectroscopy
- time-resolved fast spectroscopy