Abstract
Nanoplastics (NPs) accumulating in the environment pose a severe environmental threat, harming both animals and humans. This urgently calls for reliable, fast and easy to use sensing methods. In this work we investigated the use of an electrolyte-gated field-effect-transistor (EG-FET) based sensor with a carbon nanotube (CNT) semiconducting channel (EGCNTFET) for the detection of NPs in aquatic environments. A
variety of NP models, made from different materials and with different surface modifications, are nowadays available. Here, we compared the EG-CNTFET sensitivity using two NP models: polystyrene NPs with both non-functionalized and carboxylated surface. The EG-CNTFET devices presented a sensitivity of 22.6 μA/(1mg/ml) for non-functionalized NPs, and of 20.9 μA/(1mg/ml) for carboxylated NPs. This sensitivity is attributed to the hydrophobic interaction between CNTs and the NPs. Indeed, through atomic force microscopy, NPs were observed on the CNTs network. This study offers a starting point for future use of EG-FET-based sensors for detection of environmentally relevant NPs.