Development of a dielectrophoresis-assisted surface plasmon resonance fluorescence biosensor for detection of bacteria

Chiaki Kuroda, Ryota Iizuka, Yoshimichi Ohki, Makoto Fujimaki

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    To detect biological substances such as bacteria speedily and accurately, a dielectrophoresis-assisted surface plasmon resonance (SPR) fluorescence biosensor is being developed. Using Escherichia coli as a target organism, an appropriate voltage frequency to collect E. coli cells on indium tin oxide quadrupole electrodes by dielectrophoresis is analyzed. Then, E. coli is stained with 4$,6-diamidino-2-phenylindole (DAPI). To clearly detect fluorescence signals from DAPI-stained E. coli cells, the sensor is optimized so that we can excite SPR on Al electrodes by illuminating 405 nm photons. As a result, the number of fluorescence signals is increased on the electrodes by the application of a low-frequency voltage. This indicates that E. coli cells with a lower permittivity than the surrounding water are collected by negative dielectrophoresis onto the electrodes where the electric field strength is lowest.

    Original languageEnglish
    Article number057001
    JournalJapanese Journal of Applied Physics
    Issue number5
    Publication statusPublished - 2018 May 1


    ASJC Scopus subject areas

    • Engineering(all)
    • Physics and Astronomy(all)

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