Novel biomass-derived porous-graphitic carbon coated iron oxide nanocomposite as an efficient electrocatalyst for the sensitive detection of rutin (vitamin P) in food and environmental samples

Design and development of inexpensive, portable, and eco-friendly electrochemical non-enzymatic sensors with high selectivity and sensitivity is pivotal in analytical chemistry. In this regard, we have developed a highly porous graphitic-activated carbon (GAC, derived from tamarind fruit shell biomass) coated iron oxide (Fe₂O₃) nanocomposite (Fe₂O₃/GAC) for the efficient detection of rutin (vitamin p). Fe₂O₃/GAC nanocomposite was prepared using a facile green synthesis method and thoroughly characterized using SEM, XRD, and XPS techniques. As-prepared Fe₂O₃/GAC nanocomposite was deposited over a screen printed electrode (SPE) to fabricate Fe₂O₃/GAC/SPE and utilized as a non-enzymatic sensor for the electrochemical determination of rutin in food and environmental samples. The modified electrode was characterized using cyclic voltammetry and electrochemical impedance spectroscopy techniques, which witnessed the excellent conductivity of the developed sensor. The fabricated Fe₂O₃/GAC/SPE nanocomposite exhibited a set of redox peaks in the presence of rutin, corresponding to the electrochemical redox feature of rutin (rutin to 3′,4′-diquinone). Further, the modified electrode displayed excellent electrocatalytic characteristics towards the oxidation of rutin, based on which a differential pulse voltammetry-based sensor was developed for rutin determination. The developed non-enzymatic sensor has shown prominent performance towards rutin detection in a wide linear range from 0.1 to 130 μM with an excellent detection limit of 0.027 μM. The enhanced electrocatalytic response could be ascribed to the synergistic effect of Fe₂O₃ and GAC on the developed probe. Moreover, the developed sensor was successfully utilized for real-time detection of rutin in various samples.