Portable Paper-Based Nucleic Acid Enrichment for Field Testing

Point-of-care testing (POCT) can be the method of choice for detecting infectious pathogens; these pathogens are responsible for not only infectious diseases such as COVID-19, but also for certain types of cancers. For example, infections by human papillomavirus (HPV) or Helicobacter pylori (H. pylori) are the main cause of cervical and stomach cancers, respectively. COVID-19 and many cancers are treatable with early diagnoses using POCT. A variety of nucleic acid testing have been developed for use in resource-limited environments. However, questions like unintegrated nucleic acid extraction, open detection systems increase the risk of cross-contamination, and dependence on expensive equipment and alternating current (AC) power supply, significantly limit the application of POCT, especially for on-site testing. In this paper, a simple portable platform is reported capable of rapid sample-to-answer testing within 30 min based on recombinase polymerase amplification (RPA) at a lower temperature, to detect SARS-CoV-2 virus and H. pylori bacteria with a limit of detection as low as 4 x 10(2) copies mL(-1). The platform used a battery-powered portable reader for on-chip one-pot amplification and fluorescence detection, and can test for multiple (up to four) infectious pathogens simultaneously. This platform can provide an alternative method for fast and reliable on-site diagnostic testing.

Automated summary

Point-of-care testing (POCT) is a preferred method for detecting infectious pathogens, including COVID-19 and certain cancers. However, the application of POCT is limited by issues like unintegrated nucleic acid extraction, open detection systems that increase the risk of cross-contamination, and dependence on expensive equipment and AC power supply. This paper reports a portable platform based on recombinase polymerase amplification (RPA) that can rapidly detect SARS-CoV-2 virus and H. pylori bacteria within 30 minutes, with a low limit of detection. The platform uses a battery-powered portable reader for on-chip amplification and fluorescence detection, and can test for multiple pathogens simultaneously.