Abstract
An analytical method is developed for ultrasensitive detection of citrinin using double isothermal amplification and CRISPR-Cas12a. Gold nanoparticles (AuNPs) modified with antigen and thiol-terminated, single-strand DNA (ssDNA) are used as a probe. The antigen-modified AuNPs compete with citrinin to bind to magnetic beads coated with an anticitrinin antibody. After a simple magnetic separation, the AuNPs are collected, and the ssDNA are released after they are washed with a dithiothreitol solution. The ssDNA is first amplified by an exponential amplification reaction and then used as a primer in a subsequent hybridization chain reaction to produce double-stranded DNA (dsDNA) that contains a protospacer adjacent motif to allow recognition by CRISPR-Cas12a. The dsDNA activates the Cas12a-gRNA to cleave a reporter ssDNA to generate a fluorescence signal. The developed analytical method has a low detection limit (0.127 ng mL–1) and a wide linear range (0.005–500 μg mL–1) for detection of citrinin. For detection of citrinin in oat and flour, recoveries of 97–104% and 105–111% are obtained, respectively. By combining double isothermal amplification with CRISPR-Cas12a, ultrahigh sensitivity and selectivity can be achieved for detection of toxins in food.
Original language | English |
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Pages (from-to) | 1997-2005 |
Number of pages | 9 |
Journal | ACS Agricultural Science and Technology |
Volume | 1 |
Issue number | 10 |
DOIs | |
Publication status | Published - 2021 Oct 25 |
Subject classification (UKÄ)
- Analytical Chemistry
- Biological Sciences
Free keywords
- Ultrasensitive detection
- Biobarcode
- CRISPR-Cas12a
- Exponential amplification reaction
- Hybridization chain reaction
- Citrinin