16 May 2017 Sensing of Streptococcus mutans by microscopic imaging ellipsometry
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Microscopic imaging ellipsometry is an optical technique that uses an objective and sensing procedure to measure the ellipsometric parameters Ψ and Δ in the form of microscopic maps. This technique is well known for being noninvasive and label-free. Therefore, it can be used to detect and characterize biological species without any impact. Microscopic imaging ellipsometry was used to measure the optical response of dried Streptococcus mutans cells on a glass substrate. The ellipsometric Ψ and Δ maps were obtained with the Optrel Multiskop system for specular reflection in the visible range ( λ = 450 to 750 nm). The Ψ and Δ images at 500, 600, and 700 nm were analyzed using three different theoretical models with single-bounce, two-bounce, and multibounce light paths to obtain the optical constants and height distribution. The obtained images of the optical constants show different aspects when comparing the single-bounce analysis with the two-bounce or multibounce analysis in detecting S. mutans samples. Furthermore, the height distributions estimated by two-bounce and multibounce analyses of S. mutans samples were in agreement with the thickness values measured by AFM, which implies that the two-bounce and multibounce analyses can provide information complementary to that obtained by a single-bounce light path.
© 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
Mai Ibrahim Khaleel, Yu-Da Chen, Ching-Hang P. Chien, Yia-Chung Chang, "Sensing of Streptococcus mutans by microscopic imaging ellipsometry," Journal of Biomedical Optics 22(5), 056005 (16 May 2017). https://doi.org/10.1117/1.JBO.22.5.056005 . Submission: Received: 29 January 2017; Accepted: 21 April 2017
Received: 29 January 2017; Accepted: 21 April 2017; Published: 16 May 2017

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