  The synthesis of polyynes during their formation by pulsed laser ablation in
liquid (i.e. acetonitrile) has been analyzed by in-situ surface-enhanced Raman
spectroscopy (SERS). A polyethylene pellet, functionalized with silver
nanoparticles and placed into the ablation medium, served as SERS active
surface. This innovative approach granted the possibility to investigate the
dynamics of formation and degradation of polyynes with a time-resolution of a
few seconds, starting from the early stages of ablation when the concentration
is low. The processes occurring during the synthesis have been studied
comparing the in-situ SERS signal of polyynes and byproducts in the solution.
The different kinetics of short and long polyynes have been investigated by
their in-situ SERS signal, exploring the final distribution of chain lengths.
Ex situ UV-Vis and high-performance liquid chromatography confirmed the
observations gained from in-situ SERS data and validated this innovative
in-situ and in-operando analysis.
