Sensitive Detection of Glyphosate by a Water-Gated Organic Transistor

Abstract

In this study, we developed a glyphosate (GlyP) sensor based on a water-gated organic field-effect transistor (WG-OFET). The WG-OFET has a side-gated structure, which is easier to fabricate compared to the conventional multi-stacked OFET structure. A carboxylate-functionalized polythiophene (PT) was employed as the organic semiconductor and receptor, which enabled a competitive assay among PT, Cu 2+ , and GlyP in water. The WG-OFET sensor achieved highly sensitive and selective detection ( i.e. limit of detection = 0.26 ppm), which was lower than the maximum approved GlyP level (0.7 ppm) in drinking water in the United States. This study demonstrates the promising potential of WG-OFET as an electronic sensor device for the detection of analytes in aqueous media.