Eco-friendly synthesis of aloe vera plant extract decorated iron tungstate nanorods immobilized nafion based on the selective and sensitive determination of theophylline in blood serum, black tea and urine samples

Abstract This paper describes a selective and sensitive detection of bronchodilators drug (theophylline) using aloe vera plant extract decorated iron tungstate nanorods (AFW) immobilized Nafion (Nf) modified glassy carbon electrode (GCE) (AFW/Nf/GCE). The AFW was synthesized by the co-precipitation method and characterized by UV-visible spectroscopy, x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), elemental analysis (EDX) and electrochemical studies. Interestingly, the oxidation of theophylline with AFW/Nf/GCE displayed, a superior electrocatalytic activity, when compared with bare GCE and iron tungstate (FW) modified GCE. Besides, oxidation of theophylline in electrochemical sensor revealed that the tremendous current response linear ranges from 0.1-160μM and low detection limit (LOD) 0.0028μM. The electrochemical sensor studies showed a tremendous selectivity in biological and food samples. Besides, it showed manifested stability and reproducibility. The proposed method has been applied for the selective determination of theophylline in real samples such as human serum, black tea, and urine samples.