Raman spectra of the 1,372 cm−1 furfural peak. Panels (A), (B), and (C) are Raman spectra of the 1,372 cm−1 furfural peak acquired in the aqueous phase and the equilibrated PDMS and epoxy phases, respectively. Three different aqueous concentrations are shown: (I) 50 mM, (II) 35 mM, and (III) 20 mM. Data points are raw data, and lines are the Voigt curve fits. The normalize signal intensity is shown as counts per second (cps).