An integrated sample-to-answer graphene microchip for ultrafast detection of multiple microorganisms

The integrated detection of nucleic acids is a molecular biological technology integrating the entire process of nucleic acid detection into a "sample-to-answer" system, which is widely used in microbial identification and disease diagnosis. Although the integrated detection of nucleic acids has the advantages of fully-enclosed system and simple operation, it still faces challenges like dependence on bulky equipment, complex design, and long detection time. To address these challenges, we have proposed and fabricated an integrated graphene microchip for ultra-fast detection of multiple microorganisms. This microchip is composed of two main regions: the electrolysis-extraction region and the isothermal amplification-detection region. In the electrolysis-extraction region, the microchip was equipped with the micron-structured graphene interdigital electrode and a regular battery for power supply, and the nucleic acids of H. pylori were extracted only in 1.0 s by electrolysis. Then in the isothermal amplification-detection region, the nucleic acids of H. pylori were detected in less than 9 min at a concentration of 10 CFU/µL. As a result, the detection time of the whole process were controlled in merely 9 min. In addition, this integrated graphene microchip has three parallel channels for simultaneous detection of oral microorganisms, e.g., C. albicans, S. aureus and H. pylori. These characteristics make our integrated graphene microchip promising to contribute to the development in integrated technology of nucleic acid detection and be widely used at various medical structures or on-site environments such as home testing.