Rapid,　specific,　and　on-site　detection　of　virulent　foodborne　pathogenic　strains　plays　a　key　role　in　controlling　food　safety.　In　this　work,　an　ultrasensitive　and　specific　Phage@DNAzyme　signal　probe　was　designed　to　detect　foodborne　pathogens.　The　proposed　sensing　probe　was　composed　of　the　selected　phage　and　functionalized　DNAzyme,　which　realized　the　specific　recognition　of　target　foodborne　pathogens　at　the　strain　level　and　the　efficient　catalysis　of　copper(II)　based　azide-alkyne　cycloaddition　(CuAAC)　click　reaction　with　fluorescent　signal,　respectively.　As　a　proof　of　concept,　the　virulent　Escherichia　coli　O157:H7　(E.　coli　O157:H7)　as　the　representative　analyte　was　first　enriched　and　purified　from　the　complex　food　samples　by　a　4-mercaptophenylboronic　acid-modified　gold　slide.　Following,　the　Phage@DNAzyme　probes　were　specifically　combined　with　the　captured　E.　coli　O157:　H7　and　catalyzed　the　click　reaction　between　3-azido-7-hydroxycoumarin　and　3-butyn-1-ol　with　the　assistance　of　Cu(II)　to　generate　a　visual　fluorescent　signal.　Finally,　the　corresponding　fluorescent　signals　were　measured　by　a　smartphone　to　quantify　the　target　concentrations.　Under　optimized　conditions,　the　bioassay　exhibited　a　wide　linear　range　from　102　to　108　CFU/mL　and　the　detection　limit　was　50　CFU/mL　(S/N　=　3).　It　was　further　extended　to　the　detection　of　another　foodborne　pathogen　Salmonella　typhimurium　with　satisfying　sensing　performances.　This　work　gives　a　new　path　for　developing　rapid,　specific,　and　on-site　detection　methods　for　trace　levels　of　pathogenic　strains　in　foods.　©　2023　American　Chemical　Society.