Lab-on-paper for point-of-care detection of pesticides: A review

The growing population and increasing food demand have caused an increase in pesticide consumption by farmers to prevent crop loss and maintain yield. While effective, pesticides pose serious risks to the environment, animals and humans, making accurate detection of pesticides essential. Advanced tools such as high-performance liquid chromatography and gas chromatography–mass spectrometry offer sensitive and accurate detection of pesticides but cannot be deployed for on-site use because of their high cost and complexity. In response, there has been a surge in the development of point-of-care devices, many of which utilize paper as a substrate. These devices, commonly known as lab-on-paper devices, provide a low-cost, portable and qualitative method for detecting pesticide residues in a variety of samples, including environmental and biological samples. These devices have employed novel recognition elements such as enzymes, aptamers, and nanomaterials and have integrated new age technologies such as artificial intelligence (AI) and machine learning (ML) for the enhanced optical detection of pesticides. This review highlights recent advancements in lab-on-paper technologies that utilize optical signals for the detection of pesticides. Furthermore, we highlight developments involving lateral flow assays for pesticide detection and discuss the challenges in commercialization and real-life settings.