Nanoparticles of Neodymium Tungstate on Reduced Graphene Oxide for Highly Sensitive Electrochemical Detection of Morin in Food

Abstract

A nanocomposite comprising neodymium tungstate (Nd₂WO₆) and reduced graphene oxide (rGO) was developed as an advanced electrochemical sensing platform, leveraging the synergistic properties of both components. Nd₂WO₆, a rarely explored rare-earth tungstate, provides distinctive redox activity, high chemical stability, and efficient electron transfer, while rGO, synthesized via a green reduction using ascorbic acid, contributes high conductivity, increased surface area, and sustainable material design. The intimate integration of Nd₂WO₆ nanoparticles with rGO sheets was confirmed by structural and morphological analyses, ensuring effective electron transport and enhanced active sites. The sensor was evaluated for the detection of morin, a biologically active flavonoid present in fruits and vegetables, which requires monitoring due to potential cytotoxicity and interference with drug metabolism upon excessive intake. The Nd₂WO₆-rGO modified electrode demonstrated exceptional performance, achieving a nanomolar detection limit (0.827 nM) and quantification limit (2.73 nM), a broad linear range of 6.25 nM–189.3 μM, and excellent reproducibility and operational stability. Importantly, the method enabled direct analysis of real samples with satisfactory recoveries without the need for complex pretreatment. This study highlights the employment of Nd₂WO₆ as a rare-earth tungstate in combination with environmentally friendly rGO to construct a highly efficient, stable, and sustainable electrochemical sensor. The results establish the Nd₂WO₆-rGO nanocomposite as a promising platform for rapid, reliable, and practical food safety monitoring.