Voltammetric analysis of As3+ and sulfamethoxazole on an electrode modified with a composite of carbon dots and graphitic carbon nitride
Theo H.G. Moundzounga, Moses G. Peleyeju, Benjamin O. Orimolade, Abimbola M. Olatunde, Winny Kgabo Maboya, Samson O. Akpotu, Muntuwenkosi Chili, Michael J. Klink
Abstract
The need to monitor priority pollutants in the aqueous environments cannot be overemphasised. Herein, we employed a glassy carbon electrode (GCE) modified with a nanocomposite of carbondots (CDs) and graphitic carbon nitride (g-C 3 N 4 ) for the determination of arsenic(III) and sulfamethoxazole (SMX) in aqueous media. The composite material, synthesised by microwave technique, was characterised by transmission electron microscopy and X-ray diffraction. The electrochemical behaviours of the modified glassy electrode were also investigated using cyclic voltammetry (CV) and differential pulsed voltammetry. The findings indicated that the constructed g-C 3 N 4/CDs/GCE electrode markedly improved the oxidation peak currents of both analytes, suggesting enhanced sensitivities. Notably, the working ranges and detection limits obtained for arsenic (III) were 2 – 10 and 1.64 μM and 0.3 – 0.1 and 0.10 μM for SMX, respectively. Though, copper, cadmium, lead and zinc were observed to interfere with the determination of As 3+ , but EDTA was used to mask these interfering effects of the cations. The modified electrode (g- C 3 N 4/CDs/GCE) was used to quantify arsenic and SMX in spiked aqueous solution by standard addition and percentage recoveries of 98–100% and 80–105% were recorded for As 3+ and SMX respectively. Thus, the findings of this study established that the investigated nanocomposite material represents an easy and sensitive platform for the determination of As 3+ and SMX in the aqueous environments to curb environmental pollution.