For the TEM observations, the extracts of a volume of ~20 mL were concentrated to a volume of about 0.7 mL, then ethanol of 20 mL was added. This solvent exchange is useful to minimize the amount of hydrocarbon adsorbates on the sample. Then, 5 μL of the suspension was collected with a pipette and drop casted onto a TEM microgrid. The TEM grid was dried in vacuum using a dry pumping station for ~2 h to remove solvent.