Presentation
17 September 2018 Optical trapping and Gram type differentiation of living bacteria with 2D photonic crystal cavities (Conference Presentation)
Author Affiliations +
Abstract
The development of methods for the rapid analysis of pathogenic bacteria or viruses is of crucial interest in the clinical diagnosis of infectious diseases. In the last decade, optical resonators integrated with microfluidic layers arose as promising tools for biological analysis, notably thanks to their ability to trap objects with low powers, beneath the damage threshold of biological entities, and with a small footprint. Moreover, the resonant nature of optical cavities allows for the simultaneous acquisition of information on the trapped objects, thanks to the feedback effect induced by the specimen on the trapping field itself. Here we report on the trapping and on the Gram-type differentiation of seven types of living bacteria in an optofluidic system based on an optical cavity consisting in a large hole in a 2D silicon photonic crystal membrane. The hollow nature of the resonant cavity results in a large overlap between the confined field and the hollow volume, allowing for a maximum interaction between the trapping field and the trapped cell. The optical cavity was excited at the resonance wavelength and the shift induced by the trapped bacteria was analysed. To test the trapping capabilities of our structure, we investigated seven types of bacteria, featuring different morphologies, Gram-types and mobilities (presence or absence of flagella). The analysis of the resonance shift yielded Gram typing in a label-free and not destructive way, due to differences in the refractive index and in the deformability of the cell wall. In particular, Gram negative bacteria showed a larger shift.
Conference Presentation
© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Rita Therisod, Manon Tardif, Emmanuel Picard, Pierre R. Marcoux, Victor Gaude, Jean-Baptiste Jager, Emmanuel Hadji, David Peyrade, and Romuald Houdré "Optical trapping and Gram type differentiation of living bacteria with 2D photonic crystal cavities (Conference Presentation)", Proc. SPIE 10723, Optical Trapping and Optical Micromanipulation XV, 107231Z (17 September 2018); https://doi.org/10.1117/12.2319666
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KEYWORDS
Bacteria

Photonic crystals

Optical resonators

Optical tweezers

Biological research

Laser damage threshold

Microfluidics

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