Label-free incoherent super-resolution optical microscopy

Nikhil Jayakumar; Luis E. Villegas-Hernandez; Weisong Zhao; Hong Mao; Firehun T Dullo; Jean Claude Tinguley; Krizia Sagini; Alicia Llorente; Balpreet Singh Ahluwalia

arXiv · 2301.03451

Label-free incoherent super-resolution optical microscopy

Nikhil Jayakumar·Luis E. Villegas-Hernandez·Weisong Zhao·Hong Mao·Firehun T Dullo·Jean Claude Tinguley·Krizia Sagini·Alicia Llorente·Balpreet Singh Ahluwalia

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Abstract

The photo-kinetics of fluorescent molecules have enabled the circumvention of far-field optical diffraction-limit. Despite its enormous potential, the necessity to label the sample may adversely influence the delicate biology under investigation. Thus, continued development efforts are needed to surpass the far-field label-free diffraction barrier. The coherence of the detected light in label-free mode hinders the application of existing super-resolution methods based on incoherent fluorescence imaging. In this article, we present the physics and propose a methodology to circumvent this challenge by exploiting the photoluminescence of silicon nitride waveguides for near-field illumination of unlabeled samples. The technique is abbreviated EPSLON, Evanescently decaying Photoluminescence Scattering enables Label-free Optical Nanoscopy. We demonstrate that such an illumination has properties that mimic the photo-kinetics of nano-sized fluorescent molecules. This allows for developing a label-free incoherent system that is linear in intensity, and stable with time thereby permitting the application of techniques like structured illumination microscopy (SIM) and intensity-fluctuation-based optical nanoscopy (IFON) in label-free mode to circumvent the diffraction limit.

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Nikhil Jayakumar, Luis E. Villegas-Hernandez, Weisong Zhao, Hong Mao, Firehun T Dullo, Jean Claude Tinguley, Krizia Sagini, Alicia Llorente, Balpreet Singh Ahluwalia. 2023-01-09. Label-free incoherent super-resolution optical microscopy. https://arxiv.org/abs/2301.03451

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