Plasmonically Enhanced CRISPR/Cas13a-Based Bioassay for Amplification-Free Detection of Cancer-Associated RNA.

Novel methods that enable sensitive, accurate and rapid detection of RNA would not only benefit fundamental biological studies but also serve as diagnostic tools for various pathological conditions, including bacterial and viral infections and cancer. Although highly sensitive, existing methods for RNA detection involve long turn-around time and extensive capital equipment. Here, an ultrasensitive and amplification-free RNA quantification method is demonstrated by integrating CRISPR-Cas13a system with an ultrabright fluorescent nanolabel, plasmonic fluor. This plasmonically enhanced CRISPR-powered assay exhibits nearly 1000-fold lower limit-of-detection compared to conventional assay relying on enzymatic reporters. Using a xenograft tumor mouse model, it is demonstrated that this novel bioassay can be used for ultrasensitive and quantitative monitoring of cancer biomarker (lncRNA H19). The novel biodetection approach described here provides a rapid, ultrasensitive, and amplification-free strategy that can be broadly employed for detection of various RNA biomarkers, even in resource-limited settings.