Multimodal detection of flap endonuclease 1 activity through CRISPR/Cas12a trans-cleavage of single-strand DNA oligonucleotides

Microfluidic particle counter visualizing mucosal antibodies against SARS-CoV-2 in the upper respiratory tract for rapid evaluation of immune protection

“…A LOD of 14.0 ng mL −1 was achieved, which prevents type I and type II errors (less than 5% false positive/negative rate; see the ESI† for details). 38–40…”

“…A LOD of 14.0 ng mL −1 was achieved, which prevents type I and type II errors (less than 5% false positive/negative rate; see the ESI † for details). [38][39][40] To verify the compatibility with human samples, 87 volunteers with at least two doses of vaccination were recruited in Hong Kong. The anti-spike RBD IgG concentrations of the 87 total NS samples were first measured using ELISA (Fig.…”

CRISPR/Cas12a-enhanced single-molecule counting for sensitive detection of flap endonuclease 1 activity at the single-cell level

“…16 To further improve the assay sensitivity, a series of nucleic acid amplification strategies have been introduced for amplified sensing of FEN1, but they often require the cooperation of multiple enzymes ( e.g. , ligase, DNA polymerase, nicking enzyme, and RNA polymerase) 17–23 and suffer from high background derived from target-independent amplification. The development of simple, selective, and sensitive methods for FEN1 assay is still highly required.…”

“…However, many fluorescence FEN1 assays require complicated procedures for the synthesis of functional nanomaterials such as graphene oxide, 13 gold nanostars, 14 metal-organic frameworks, 15 and silver nanoclusters. 16 To further improve the assay sensitivity, a series of nucleic acid amplification strategies have been introduced for amplified sensing of FEN1, but they often require the cooperation of multiple enzymes (e.g., ligase, DNA polymerase, nicking enzyme, and RNA polymerase) [17][18][19][20][21][22][23] and suffer from high background derived from target-independent amplification. The development of simple, selective, and sensitive methods for FEN1 assay is still highly required.…”

“…This biosensor exploits single CRISPR/Cas12a enzyme to amplify the target signal directly and efficiently, avoiding the complicated reaction schemes and non-specific amplification involved in the nucleic acid amplification-based FEN1 assays. [17][18][19][20][21][22][23] Moreover, the assembly of multiple HP1/HP2 duplexes on a single MB can enhance the local concentration of probes, 34 greatly improving the FEN1 catalytic efficiency. In addition, the introduction of a magnetic separation strategy can significantly avoid the interferences from the uncleaved probes and complex biological samples.…”