Disposable carbon dots modified screen printed carbon electrode electrochemical sensor strip for selective detection of ferric ions

Abstract

A disposable electrochemical sensor strip based on carbon nanodots (C-Dots) modified screen printed carbon electrode (SPCE) was fabricated for selective detection of ferric ions (Fe3+) in aqueous solution. C-Dots of mean diameters within the range of 1-7 nm were synthesized electrochemically fromspent battery carbon rods.The analytical performance of this electrochemical sensor strip was characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).The deposition ofC-Dots had enhanced the electron-Transfer kinetics and current intensity of the SPCE remarkably by 734% as compared to that of unmodified SPCE. Under optimized conditions, the electrochemical sensor strip exhibited a linear detection range of 0.5 to 25.0 ppmFe3+ with a limit of detection (LOD) of 0.44 ± 0.04 ppm (at S/N ratio = 3). Validation of results by the electrochemical sensor strip was done by comparing analysis results obtained using an Atomic Absorption Spectrometer (AAS).