3D-nanocubes of N-doped carbon quantum dots adorned manganese oxide: A functional electrocatalyst for the sensitive detection of sulfadiazine

Abstract

Rapid monitoring of antibiotic drugs has received a lot of attention due to the great global demand for cost-effective and high-efficacy medications. Herein, a simple fabrication of nitrogen-doped carbon quantum dots adorned with manganese oxide nanocubes (N-CQD@Mn3O4 NCs) is reported, and their electrocatalytic activity has been used to detect the antibiotic drug sulfadiazine (SDZ). The impact of experimental parameters such as active material loading concentration, scan rate, pH, analyte accumulation duration, and SDZ concentration, were analyzed against the oxidation peak signals of SDZ. The N-CQD@Mn3O4 NCs modified electrode demonstrated a well-resolved oxidation peak at the lowest oxidation potential of 0.89 V vs. Ag/AgCl, owing to the high active sites, catalytic efficiency, and synergistic impact of N-CQDs and Mn3O4, Notably, the modified electrode exhibited excellent electrochemical performance in terms of low detection limit (0.014 µM), high sensitivity (2.75 µA µM−1 cm−2), and appreciable linear range (0.5 – 663 µM). Moreover, good reproducibility and storage stability were also achieved. Finally, the proposed sensor demonstrated its viable application by detecting the SDZ in the human urine samples with satisfactory results (〜99%).