Journal
SENSORS AND ACTUATORS B-CHEMICAL
Volume 347, Issue -, Pages -Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.snb.2021.130586
Keywords
CRISPR-Cas12a; G-quadruplex; Colorimetric detection; Pathogenic bacteria; Smartphone
Funding
- National Natural Science Foundation of China [32072309, 21672161, 81503086]
- Tianjin Municipal Science and Technology Committee [19JCYBJC27800]
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science Technology [19PTSYJC00060]
Ask authors/readers for more resources
A G-quadruplex-based CRISPR-Cas12a bioassay was developed for high sensitivity and visualization detection of Salmonella. The method achieved a detection limit of 1 CFU/mL for Salmonella and successfully detected the bacteria in real food samples.
Foodborne diseases, caused by pathogenic bacteria, severely threaten global human health and cause a financial burden. Rapid, sensitive and on-site detection of pathogenic bacteria is significant. The existing methods have different defects, such as time-consuming and inconvenient. In this study, we developed a G-quadruplex-based CRISPR-Cas12a bioassay for pathogenic bacteria detection with high sensitivity and visualization capability. Salmonella was used as the detection model. Simply, the amplicons of Salmonella specific invA gene activated the trans-cleavage activity of Cas12a and triggered CRISPR-Cas12a based indiscriminate degradation of single stranded DNAs (ssDNAs). The ssDNAs were designed with the guanine-rich sequence and formed a stable Gquadruplex DNAzyme by adding K+. This DNAzyme could catalyze the TMB-H2O2 reaction in the presence of hemin, leading to an increase in absorbance at 454 nm and a color change. This change can be readily differentiated by the naked eyes as well as a smartphone with a Color Picker App. With this strategy, the limit of detection (LOD) for Salmonella was 1 CFU/mL with no cross-reactivity. A linear relationship (R-2 = 0.993) between the absorbance and the concentration of Salmonella was obtained. Furthermore, G-quadruplex-based CRISPR-Cas12a bioassay was successfully applied for sensing Salmonella in real food samples. This work not only expands the reach of CRISPR-Cas based biosensing but also provides a novel pathogenic bacteria detection method with high sensitivity, specificity and on-site capability.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available