Luminol-based Ternary Electrochemiluminescence Nanospheres As Signal Tags And Target-triggered Strand Displacement Reaction As Signal Amplification For Highly Sensitive Detection Of Helicobacter Pylori

Helicobacter pylori（H.pylori）,a spiral micro anaerobic gram-negative bacteria pathogen,was isolated from the gastric mucosa biopsy tissue of patients with chronic active gastritis.H.pylori is considered to be a crucial causative agent in the pathogenesis of chronic gastritis,gastroduodenal ulcer diseases,mucosa-associated lymphoid tissue lymphoma and gastric adenocarcinoma.Moreover,about half of the world’s population has been infected with H.pylori and H.pylori was listed on carcinogens list of Group 1 by International Agency for Research on Cancer（IARC）.Therefore,it is of great importance to detect H.pylori sensitively for monitoring the treatment and prognosis of H.pylori infection associated diseases.At present,the existing detection methods can’t achieve sensitive detection of H.pylori.Herein,a new method of ternary electrochemiluminescence nanosphere based on luminol was designed for the highly sensitive detection of H.pylori.Herein,a novel ternary electrochemiluminescence（ECL）nanosphere containing the emitter of luminol（Lum）,the coreactant of polyethylenimine（PEI）and the coreaction accelerator of amino-terminated perylene derivative（PTC-NH₂）was prepared for the first time,which possessed strong ECL emission due to self-enhanced intramolecular coreaction of PEI-Lum and coreaction acceleration of PTC-NH₂ to Lum/H₂O₂ system.Combining the Lum-based ternary ECL nanosphere with target-triggered strand displacement reaction,a highly sensitive and enzyme-free biosensor was constructed for.This developed ECL biosensing method exhibited a wide linear range from 10 fM to 10 nM and a detection limit down to 2.4 fM,which was successfully applied for Helicobacter pylori assay in serum.Thus,this work provides a new avenue to develop high-performance ECL nanomaterials and an enzyme-free bioassay to be applied in the clinical molecular diagnosis of gastric diseases.