Quantum Dot\nReporters Designed for CRISPR-Based Detection\nof Viral Nucleic Acids

Diagnostic methods based on CRISPR technology have shown\ngreat\npotential due to their highly specific, efficient, and sensitive detection\ncapabilities. Although the majority of the current studies rely on\nfluorescent dye-quencher reporters, the limitations of fluorescent\ndyes, such as poor photostability and small Stokes shifts, urgently\nnecessitate the optimization of reporters. In this study, we developed\ninnovative quantum dot (QD) reporters for the CRISPR/Cas systems,\nwhich not only leveraged the advantages of high photoluminescence\nquantum yield and large Stokes shifts of QDs but were also easily\nsynthesized through a simple one-step hydrothermal method. Based on\nthe trans-cleavage characteristics of Cas12a and Cas13a, two types\nof QD reporters were designed, the short DNA strand and the hybridization-based\nQD reporters, achieving the detection of DNA and RNA at the pM level,\nrespectively, and validating the performance in the analysis of clinical\nsamples. Furthermore, based on the unique property of QDs that allowed\nmulticolor emission under one excitation, the application potential\nfor simultaneous detection of diseases was further investigated. Taken\ntogether, this work proposed novel QD reporters that could be applied\nto the various CRISPR/Cas systems, providing a new toolbox to expand\nthe diagnosis of bioanalytical and biomedical fields.