Polarization-Sensitive Surface-Enhanced In Situ Photoluminescence Spectroscopy of S. aureus Bacteria on Gold Nanospikes

Autor: Irina Saraeva, Sergey I. Kudryashov, Pavel Danilov, Nikolay Busleev, Eteri R. Tolordava, Andrey A. Rudenko, Dmitriy Zayarny, Andrey Ionin, Yulia M. Romanova
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Sensors, Vol 20, Iss 9, p 2466 (2020)
Druh dokumentu: article
ISSN: 20092466
1424-8220
DOI: 10.3390/s20092466
Popis: We report the possibility of a time-resolved bacterial live/dead dynamics observation with the use of plasmonic nanospikes. Sharp nanospikes, fabricated on a 500-nm thick gold film by laser ablation with the use of 1030-nm femtosecond pulses, were tested as potential elements for antibacterial surfaces and plasmonic luminescence sensors. Staphylococcus aureus bacteria were stained by a live/dead viability kit, with the dead microorganisms acquiring the red colour, caused by the penetration of the luminescent dye propidium iodide through the damaged cell membrane. Photoluminescence was pumped by 515-nm femtosecond laser pulses with linear (Gaussian beam), circular, azimuthal and radial (Laguerre–Gaussian beam) polarizations, exciting the transverse plasmon resonance of the nanospikes and their apex lightning-rod near-field. According to the numerical electrodynamic modeling, the observed strong increase in the photoluminescence yield for radial polarization, while slightly lower for circular and azimuthal polarizations, compared with the low luminescence intensities for the linear laser polarization, was related to their different laser–nanospike coupling efficiencies.
Databáze: Directory of Open Access Journals
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