Construction of Sr@Mn3O4/GO nanocomposite: a synergistic electrocatalyst for nitrofurantoin detection in biological and environmental samples

Abstract

Currently, antibiotic drugs based on nitro group derivatives are crucial for the treatment of urinary infections in human beings. Nonetheless, the overuse of antibiotics may cause harmful effects on the ecosystem and human health. Hence, convenient, rapid response, and cost-effective sensors are essential for controlling or monitoring the usage quantity of drugs. Electroanalytical techniques are appropriate to detect pharmaceutical compounds in real samples. In this work, we prepared a strontium–manganese oxide (Sr@Mn₃O₄) anchored graphene oxide (GO) as an efficient electrocatalyst for nitrofurantoin (NFT) detection. Spectrometric and voltammetric techniques were utilized to characterize the resultant Sr@Mn₃O₄/GO nanocomposite. The synergistic activity of Sr@Mn₃O₄ with GO enhances the specificity and sensitivity of the detection of NFT. Interestingly, the constructed Sr@Mn₃O₄/GO-modified glassy carbon electrode (GCE) showed an extensive dynamic linear range (0.01–1443 μM) and a low limit of detection (LOD of 0.0024 μM) with good sensitivity (1.73 μA μM⁻¹ cm⁻²) for NFT by differential pulse voltammetry (DPV). Moreover, the sensor exhibited excellent selectivity for NFT in the presence of biological, potentially interfering nitro compounds, and inorganic metal ions. In addition, the sensor had appreciable repeatability, reproducibility, and stability (cyclic and storage). Finally, the fabricated sensor was analyzed to quantify NFT levels in biological (human urine and serum) and environmental (tap and river water) samples with results demonstrating good recoveries.