A disposable microcapsule array chip fabricated by ice printing combined with isothermal amplification for Salmonella DNA detection

In this work, a novel microcapsule array chip was fabricated for the detection of Salmonella DNA by integrating an ice-printing technique with DNA isothermal amplification. Reaction solutions were previously sealed in the microcapsule array chip via ice printing. To protect the relatively fragile DNA isothermal amplification system, an extra polystyrene (PS) film was introduced to isolate the reaction solution from photopolymer precursor, which was proved to be a vital step for providing a clean and stable environment for DNA amplification reaction. Detection operation can be done by simply injecting sample DNA into the microcapsule by an easily accessible syringe, and the result can be directly obtained through color change within 90 minutes. This method shows good sensitivity, specificity and stability.