Effective rapid screening for sulfoxaflor insecticide in ornamental flowers by paper-based biosensing formats implementing sustainable extraction and packaging approaches

Ensuring consumers' safety and maintaining regulatory compliance requires assessing the presence of pesticide residues in agricultural products. While sulfoxaflor, a widely used sulfoximine insecticide, is effective in pest control, its environmental impact has been increasingly scrutinized. Concerns over sulfoxaflor's harm to pollinators have led to its prohibition in the EU as of 2022, making its detection a critical aspect of environmental and food safety monitoring. Here, we present an innovative, highly sensitive, semi-quantitative indirect competitive lateral flow immunoassay (icLFIA) for detecting sulfoxaflor in flower leaves. This icLFIA achieves a visual limit of detection of 4 μg/L in plant extracts by implementing a highly specific monoclonal antibody. Moreover, it has demonstrated great reproducibility, making it an eco-conscious test for routine analysis at the point of need using a simple hot water extraction and incorporating sustainable packaging. The icLFIA has been tested on commercially available ornamental flowers and critically compared against an in-house confirmatory liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. This development offers a cost-effective and reliable solution for sulfoxaflor residue assessment. The combination with a straightforward and simplified extraction protocol for flower leaves, makes it accessible to non-experts (e.g. beekeepers).