This study demonstrates a rapid visualization assay for on-spot sensing of alcohol
content as well as for discriminating methanol-containing beverages with solvent stimuliresponsive
supramolecular ionic material (SIM). The SIM is synthesized by ionic selfassembling
of imidazolium-based dication C10(mim)2 and dianionic 2, 2’-azino-bis (3-
ethylbenzothiazoline-6-sulfonic acid) (ABTS) in water and shows water stability, solvent
stimuli-responsive property, and adaptive encapsulation capability. The rationale for the
visualization assay demonstrated here is based on the combined utilization of the unique
properties of SIM, including its water stability, ethanol stimuli-responsive feature, and adaptive
encapsulation capability toward optically active rhodamine 6G (Rh6G); the addition of ethanol
into a stable aqueous dispersion of Rh6G-encapsulated SIM (Rh6G-SIM) destructs the Rh6GSIM
structure, resulting in the release of Rh6G from SIM into the solvent. Alcohol content can
thus be visualized with the naked eyes through the color change of the dispersion caused by the
addition of ethanol. Alcohol content can also be quantified by measuring the fluorescence line
of Rh6G released from Rh6G-SIM on a thin-layer chromatography (TLC) plate in response to
alcoholic beverages. By fixing the diffusion distance of the mobile phase, the length that Rh6G
mounts shows a linear relationship with alcohol content (vol %) within a concentration range
from 15% to 40%. We utilized this visualization assay for on-spot visualizing the alcohol
contents of three Chinese commercial spirits and discriminating methanol-containing counterfeit
beverages. We found that trace amount addition of methanol leads to a large increase of the
length of Rh6G on TLC plates, which provides a method to identify methanol adulterated
beverages with labeled ethanol content. This study provides a simple yet effective assay for
alcohol content sensing and methanol differentiation.