One-step detection of pesticide residues in vegetables using an inkjet printing-based test card

The overuse of pesticides has seriously threatened human safety and health, while their detection is still limited by complex procedures. An inkjet printable test card was created in this study for the quick and broad screening of organophosphorus (OP) and carbamate (CM) pesticides in one step. To ensure sensitivity and accuracy, slow-release polyvinyl alcohol (PVA) films were used as the printing substrate to separate the reaction system from the acetylcholinesterase (AChE) film. When the pesticide-containing sample was introduced to the test card, the activity of AChE was initially inhibited by pesticide residues. Subsequently, the PVA membrane dissolved, and the remaining AChE reacted with the substrate and chromogenic agent, resulting in the production of yellow products. Therefore, the levels of pesticide residues in the sample can be determined by observing color changes. Experimental results demonstrated that this test card exhibited high sensitivity, stability, and reproducibility. Moreover, this method is quick and straightforward, showing great potential in both commercial and domestic applications.