Sensitive Detection of Salmonella Based on CRISPR-Cas12a and the Tetrahedral DNA Nanostructure-Mediated Hyperbranched Hybridization Chain Reaction.
Qiqi CaiHanxing ShiMengni SunNa MaRui WangWenge YangZhaohui QiaoPublished in: Journal of agricultural and food chemistry (2022)
Salmonella severely threatens global human health and causes financial burden. The ability to sensitively detect Salmonella in food samples is highly valuable but remains a challenge. Herein, a sensitive detection method for Salmonella was developed by coupling immunomagnetic separation with the CRISPR-Cas12a system and the tetrahedral DNA nanostructure-mediated hyperbranched hybridization chain reaction (TDN-hHCR). In the detection system, the target Salmonella was immunomagnetically separated and labeled with bio-barcode DNA-modified gold nanoparticles (AuNPs), which could transfer and magnify the signal of a bacterial cell into numerous bio-barcode DNA molecules. Afterward, the bio-barcode DNA can trigger the trans-cleavage activity of CRISPR-Cas12a to inhibit the process of the TDN-hHCR to generate a fluorescence readout. Due to the high immunomagnetic separation efficiency and the effective signal amplification of CRISPR-Cas12a and the TDN-hHCR, Salmonella as low as 8 CFU/mL could be easily detected. Meanwhile, this has been applied for practical use and showed the capability to detect 17 and 25 CFU/mL in spiked milk and egg white, respectively, indicating its potential application in real samples.
Keyphrases
- crispr cas
- sensitive detection
- single molecule
- genome editing
- escherichia coli
- circulating tumor
- listeria monocytogenes
- nucleic acid
- cell free
- human health
- gold nanoparticles
- loop mediated isothermal amplification
- quantum dots
- risk assessment
- stem cells
- healthcare
- single cell
- label free
- climate change
- young adults
- bone marrow
- transcription factor
- positron emission tomography
- pet imaging