Sensitive Detection of Salmonella Based on CRISPR-Cas12a and the Tetrahedral DNA Nanostructure-Mediated Hyperbranched Hybridization Chain Reaction
Sensitive Detection of Salmonella Based on CRISPR-Cas12a and the Tetrahedral DNA Nanostructure-Mediated Hyperbranched Hybridization Chain Reaction
复制标题
DOI：
10.1021/acs.jafc.2c05831
复制
发表时间：
2022-12-13
影响因子：
6.1
通讯作者：
Qiao, Zhaohui
中科院分区：
文献类型：
--
作者：
Cai, Qiqi;Shi, Hanxing;Qiao, Zhaohui
沙门氏菌严重威胁全球人类健康，并造成经济负担。灵敏地检测食品样品中的沙门氏菌的能力是非常有价值的，但仍然是一个挑战。本研究通过将免疫磁性分离与CRISPR-Cas12a系统和四面体DNA纳米结构介导的超支化杂交链反应（TDN-hHCR）耦合，建立了沙门氏菌的灵敏检测方法。在检测系统中，目标沙门氏菌被免疫磁性分离并标记生物条形码DNA修饰的金纳米颗粒（AuNPs），其可以将细菌细胞的信号转移并放大到许多生物条形码DNA分子中。之后，生物条形码DNA可以触发CRISPR-Cas12a的反式切割活性，以抑制TDN-hHCR的过程，从而产生荧光读数。由于CRISPR-Cas12a和TDN-hHCR的高免疫磁性分离效率和有效的信号放大，可以容易地检测到低至8 CFU/mL的沙门氏菌。同时，该方法已用于实际应用，并显示出在加标牛奶和鸡蛋白色中分别检测17和25 CFU/mL的能力，表明其在真实的样品中的潜在应用。
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.