A visual detection strategy for SARS-CoV-2 based on dual targets-triggering DNA walker

SARS-CoV-2, a highly transmissible and mutagenic virus, made huge threats to global public health. The detection strategies, which are free from testing site requirements, and the reagents and instruments are portable, are vital for early screening and play a significant role in curbing the spread. This work proposed a silver-coated glass slide (SCGS)/DNA walker based on a dual targets-triggering mechanism, enzyme-catalyzed amplification, and smartphone data analysis, which build a portable visual detection strategy for the SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) gene. By this method, the detection was reflected by the ultraviolet absorbance changes and visible color changes to the naked eye which was analyzed by Red-Green-Blue (RGB) data analysis via smartphone within 30 min, simplifying the detection process and shortening the detection time. Meanwhile, the dual targets-triggering mechanism and dual signal amplification strategy ensured detection specificity and sensitivity. Further, the practicability was verified by the detection of the real sample which provided this method an application potential in SARS-CoV-2 rapid detection.