Recent advances in CRISPR/Cas systems-associated surface enhanced Raman spectroscopy biosensor towards nucleic acid detection

Nucleic acids play a decisive role in vital life processes, such as growth, heredity, and evolution, and exploring different types of nucleic acid detection techniques has always been a research hotspot worldwide. Compared to traditional nucleic acid analysis methods, surface-enhanced Raman spectroscopy (SERS) detection has advantages, such as high sensitivity, good specificity, narrow spectral bands, minimal sample requirement, simple operation, and resistance to interference from autofluorescence and water in biological samples. The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas system has gained widespread attention in the fields of gene editing and biosensors. Combining the sequence-specific recognition capability of the CRISPR/Cas system with the high sensitivity fingerprinting properties of SERS technology offers a simple, rapid, and sensitive method towards nucleic acid detection. Here, common SERS Nanotags methods for nucleic acid detection are introduced, including “sandwich assay”, “signal switch assay” and HCR signal amplification. Then, the building mechanism of CRISPR-associated SERS detection is summarized. CRISPR/Cas12a activated by crRNA can recognize and lock the complementary target double-stranded DNA (dsDNA), followed by cis-cleavage of the dsDNA and trans-cleavage of the adjacent linker ssDNA. The loss of SERS signal based on aggregation is finally used for highly sensitive detection of the target DNA. Lastly, some typical applications through the integration of CRISPR/Cas and SERS technology are introduced, such as HIV-1 dsDNA, HBV DNA and AFB1 etc.