Electrochemical sensor for determination of trace amounts of cadmium (II) in environmental water samples based on MnO₂/RGO nanocomposite

ABSTRACT

We describe a simple, efficient and selective method for electrochemical determination of trace quantities of cadmium (II). MnO₂ nanorod was synthesised by the hydrothermal method. Graphite oxide (GO) was synthesised using the modified Hummers method and reduced to RGO. The nanocomposite with 40% RGO and 60% MnO₂ (G₄₀M₆₀, w/w %) was made. Structure, morphology, and composition of the nanocomposite were studied using appropriate techniques. The experimental parameters affecting cadmium determination such as pH, deposition potential and deposition time were optimised using central composite design methods. Under optimum conditions, the calibration plots are linear in the 4.0 to 130 μg L⁻¹. The detection limits (calculated for S/N ratios of 3) are 1.12 μg L⁻¹ for Cd (II). The method was successfully applied to the determination of cadmium in environmental water samples and gave good recoveries. The student’s t-test indicated the validity and accuracy of the proposed method for the analysis of cadmium in real samples.

KEYWORDS:

• Electrochemical sensor
• cadmium (II)
• graphene
• hydrothermal

Disclosure statement

No potential conflict of interest was reported by the authors.