Dark-Field Microscopic Detection of Bacteria using Bacteriophage-Immobilized SiO2@AuNP Core-Shell Nanoparticles

Masashi Imai, Kouhei Mine, Haruna Tomonari, Jumpei Uchiyama, Shigenobu Matuzaki, Yosuke Niko, Shingo Hadano, Shigeru Watanabe

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)


To replace molecular biological and immunological methods, biosensors have recently been developed for the rapid and sensitive detection of bacteria. Among a wide variety of biological materials, bacteriophages have received increasing attention as promising alternatives to antibodies in biosensor applications. Thus, we herein present a rapid and highly selective detection method for pathogenic bacteria, which combines dark-field light scattering imaging with a plasmonic biosensor system. The plasmonic biosensor system employs bacteriophages as the biorecognition element and the aggregation-induced light scattering signal of gold nanoparticle-assembled silica nanospheres as a signal transducer. Using Staphylococcus aureus strain SA27 as a model analyte, we demonstrated that the plasmonic biosensor system detects S. aureus in the presence of excess Escherichia coli in a highly selective manner. After the sample and the S. aureus phage S13′-conjugated plasmon scattering probe were mixed, S. aureus detection was completed within 15-20 min with a detection limit of 8 × 104 colony forming units per milliliter.

Original languageEnglish
Pages (from-to)12352-12357
Number of pages6
JournalAnalytical Chemistry
Issue number19
Publication statusPublished - Oct 1 2019
Externally publishedYes

ASJC Scopus subject areas

  • Analytical Chemistry


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