Electrochemical detection of rutin in black tartary buckwheat tea and related health-care pills with new ionic liquid-based supramolecular hydrogels

As the famous naturally occurring flavonoid, rutin exists in many foods, beverages, and their processed functional products. To realize highly efficient analysis for it, a novel supramolecular hydrogel was developed as the electrode modification material for sensor. Here 12 amino acid-based ionic liquids ([Cnmim][AA]) were synthesized and 6 of them could self-aggregate to form hydrogels. Especially, all the hydrogels possessed dual sensitivities to temperature and pH, as well as relatively excellent electrocatalytic performance. A three-layer electrochemical sensor [Cnmim][AA]/MWCNTs/CS/GCE was prepared by decorating glass carbon electrode (GCE) with hydrogels, multiwalled carbon nanotubes (MWCNTs) and chitosan (CS) to detect rutin. After comprehensive characterization, computation and systematic investigation, the results indicated that Ipa was linearly related to the concentration of rutin in the range of 0.5–5 μM and 5–100 μM with a limit of detection (LOD) of 0.05 μM (S/N = 3). The selectivity, repeatability, stability and potential in electrochemical analysis of the developed supramolecular sensor were proved after analysis of black tartary buckwheat tea and related health-care pills.