Detection of Carbamates and Nitrites with a Linear Transport Unit Connected to a Paper-Based Multiplexed Colorimetric Platform for Food Safety

The COVID-19 pandemic and its associated restrictions made the concept of home testing increasingly popular. Here, we designed a linear transport unit connected to a paper-based multiplexed colorimetric platform, which can be used to test for food safety and physiological status. The device is composed of a linear transport unit and a paper-based multiplexed colorimetric reaction unit. The linear transporting unit uses the capillary phenomenon to collect samples, and the multiplexed colorimetric reaction unit can be used to detect different targets using a hydrophilic area and wax as the hydrophobic barrier. A rapid and multiplexed naked-eye readout of the colorimetric response is achieved in a few minutes. In this study, we demonstrate that the device can be used to detect nitrite, pesticides, lactate, and glycogen. It is a convenient and cheap home self-testing device that can be applied to different situations. This device could lead to earlier screening and, consequently, earlier referrals for further confirmation and treatment.