Establishment of an electrochemical sensor for detection of Helicobacter pylori based on CRISPR/Cas12a trans-cleavage activity

Helicobacter pylori ( H. pylori ) is one of the main causes of gastritis and gastric ulcers. Therefore, early detection of H. pylori is of great significance for the primary prevention of gastric cancer. Taking advantage of the trans-cleavage ability of Cas effector proteins, we developed a novel CRISPR/Cas12a-mediated electrochemical sensor for the detection of the vacAs1 gene of H. pylori . In this system, gold nanoparticles (AuNPs) were first electrodeposited on the gold electrode, which not only served to immobilize nonspecific ssDNA but also improved the conductivity of the electrode, thereby enhancing the sensitivity of the sensor. By combining recombinase-assisted amplification (RAA) with the trans-cleavage activity of CRISPR/Cas12a, changes in the amount of ssDNA were induced, further altering electronic transfer on the electrode surface. The developed CRISPR/Cas12a-based electrochemical biosensor exhibited a wider detection range (5.4 × 10 −19 −5.4 × 10 −13 M) and a low detection limit (9.5 × 10 −20 M). Moreover, the biosensor showed good recovery for the detecting H. pylori in spiked stool and artificial saliva samples. In addition, the biosensor exhibited good specificity and stability, suggesting that it may serve as a potential tool for the rapid, stable, and efficient detecting of H. pylori .