Raman spectra measurements were carried out on a confocal Raman spectrometer (HORIBA) in a back-scattering configuration with a spectral resolution of 1 cm-1. 150 μL of deionized water or binary organic-aqueous solution was injected into a customized quartz cell and excited by a laser (emission wavelength of 532 nm, output power 50 mW) at room temperature. A 10× long-workingdistance objective was used to focus laser light onto the sample and collect the scatted light. The signal was detected by a multichannel ultra-low temperature (213 K) charge-coupled array detector. The Raman spectra in the wavenumber range of 10-4000 cm-1 were recorded. Each spectrum is an accumulation of a single scan with an exposure time of 10 s.