Chip-based automated equipment for dual-mode point-of-care testing foodborne pathogens

Foodborne pathogens have a substantial bearing on food safety and environmental health. The development of automated, portable and compact devices is essential for the on-site and rapid point-of-care testing (POCT) of bacteria. Here, this work developed a micro-automated microfluidic device for detecting bacteria, such as Escherichia coli (E. coli) O157:H7, using a seashell-like microfluidic chip (SMC) as an analysis and mixing platform. The automated device integrates a colorimetric/fluorescent system for the metabolism of copper (Cu²⁺) by E. coli affecting o-phenylenediamine (OPD) for concentration analysis. A smartphone was used to read the RGB data of the chip reaction reservoir to detect colorimetric and fluorescence patterns in the concentration range of 10²-10⁶ CFU mL^-1. The automated device overcomes the low efficiency and tedious steps of traditional detection and enables high-precision automated detection that can be applied to POCT in the field, providing an ideal solution for broadening the application of E. coli detection.