Highly Selective and Sensitive Sensor Based IL and CMC-MWCNTs Nanocomposite for Rutin Determination

Rutin is a natural antioxidant flavonoid compound with anti-inflammatory, antioxidant, and antiviral effects that is used to prepare drugs with wide application in clinical treatment. Therefore, the quantitative detection of rutin has important practical significance. In this work, a novel electrochemical sensor based on glassy carbon electrodes (GCEs) modified with sodium carboxymethylcellulose (CMC), multi-walled carbon nanotubes (MWCNTs), and 1-butyl-3-methylimid (ionic liquid, IL) was developed for the super-sensitive detection of the flavonoid rutin. The properties of these modified materials were analyzed by transmission electron microscope (TEM), cyclic voltammograms (CVs), and electrochemical-impedance spectroscopy (EIS). CMC was used to disperse MWCNTs to further enhance their hydrophilicity and biocompatibility. The modified MWCNTs improved the sensitivity of rutin detection. The square-wave voltammetry (SWV) technique showed that the linear range of rutin concentration determination was 0.01 μM to 1 µM and 1 µM to 10 µM. The minimum concentration detection of rutin was 0.83 nM and 6.6 nM, respectively. The proposed sensor presented good selectivity for rutin and successfully analyzed rutin content in the pharmaceutical rutin tablets. These results are consistent with those measured by ultra-high-performance liquid chromatography (UHPLC). Therefore, this sensor has latent application value in the analysis of rutin in food and drug tablets and nutraceutical samples.