Halloysite nanotube-grafted reduced graphene oxide for sensitive electrochemical sensing of niclosamide in food, environmental and biological matrices

Abstract Niclosamide (NA) is widely used as an insecticide in agriculture and fisheries; however, its excessive application poses potential risks to food security and aquatic ecosystems. In this study, halloysite nanotubes (HNTs) were immobilized onto reduced graphene oxide (rGO) via a facile strategy to construct the HNTs-rGO nanocomposite. The introduction of HNTs effectively suppresses the interlayer buildup of rGO, which facilitates efficient interfacial electron transfer and exposes more accessible electroactive sites for NA. Under optimized conditions, this sensor has a wide detection range (0.2–40 µM) for NA with a low limit of detection (LOD) of 66.67 nM. In addition, the sensor exhibits excellent selectivity, reproducibility, and stability. Moreover, the development sensor achieved satisfactory recoveries (96%~103.3%) for NA in pill, water, cucumber, soil and field snail. All strategies proposed HNTs-rGO nanocomposite as a sustainable electrocatalyst that could be explored as an excellent candidate for detecting the NA in real sample analysis.