Application de la diffusion Raman exaltée de surface à la détection de petites molécules d'intérêt : le lactate

Surface-enhanced Raman spectroscopy, much more sensitive than normal Raman spectroscopy, was chosen as a « Green Chemistry » analytical tool to develop a quantitative approach for sodium lactate at physiological concentrations detection. Indeed, the lactate is an important biomarker involved in many diseases, including Age-Related Macular Degeneration.
Different nanoparticles’ synthesis were performed and characterized to ensure their repetability. These nanoparticles were then put into contact with lactate in order to detect this metabolite with a good sensitivity.
The next step was the functionalization of the nanoparticles’ surface with the aim of increasing sensitivity and selectivity of the detection. Among the capping agents tested, (11-mercaptoundécyl)-N,N,N-triméthylammonium bromide, a quaternary ammonium compound, was selected and the experimental conditions were optimized with the help of a design of experiments. Once again, lactate quantification was performed. Detection was possible from 0,1 to 7,5 mM.
Finally, detection of dried spots of lactate in water and in phosphate buffer was possible through the same functionalization agent.