Sensitive Determination of Rhodamine B in Real Samples at the Surface of a Multi-walled Carbon Nanotubes Paste Electrode

This paper reported a selective and sensitive electrochemical approach for detection of rhodamine B (RhB) in real samples based on a multi-walled carbon nanotubes paste electrode (MWCNT/CPE). Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronocoulometry were used to investigation of electrochemical behavior of RhB. The modified electrode showed an excellent electrocatalytic property toward the oxidation peak current of RhB. Analytical parameters such as linearity, selectivity, repeatability, and stability are also investigated. After optimizing the experimental conditions, the anodic peak current of RhB was linear to its concentration in the range of 0.1–15.0 μM, and the limit of detection was 20.0 nM (S/N=3) in 0.1 M phosphate buffer solution (pH=3.0). Furthermore, the proposed sensor was successfully applied for the detection of RhB in real samples (water samples and Hair colors) with the recoveries of 95.0–110.0%, indicating a promising potential in practical application.