Innovative electrochemical detection of emerging pollutants using MXene and carbon nanofiber modified screen-printed electrodes

Abstract

Disposable screen-printed electrodes based on carbon ink modified with MXene, and carbon nanofibers were developed as a cost-effective and simple electroanalytical platform for the sensitive detection of acid red 1 (AR) and carbaryl (CAR) in environmental samples. The electrochemical properties of the analytes were examined by cyclic voltammetry in the potential range of 0–1.2 V and at a scan rate of 50 mV s⁻¹ using 0.10 mol L⁻¹ phosphate buffer solution (pH 7.0) as the supporting electrolyte. During the anodic potential scan, two oxidation peaks were found at the potentials of 0.55 V and 1.05 V. Under optimized square wave voltammetry (SWV) conditions, the screen-printed sensor was used to construct an analytical curve with linear concentration ranges of 6.2 × 10⁻⁷ to 7.2 × 10⁻⁶ mol L⁻¹ for AR and 2.0 × 10⁻⁶ to 3.9 × 10⁻⁵ mol L⁻¹ for CAR, while the limits of detection for AR and CAR were determined to be 1.2 × 10⁻⁷ and 5.2 × 10⁻⁷ mol L⁻¹, respectively. The screen-printed sensor was found to be highly selective, sensitive, stable, reproducible, and repeatable, while also being cost-effective and unaffected by the effects of potential interferents. The proposed sensor was successfully applied for the analysis of environmental samples, where it recorded recovery rates close to 100 %.