Dual-Modality Localized Plasmonic Structured Illumination Microscopy (DM-LPSIM) for Simultaneous Fluorescence and Label-free Super-resolution Bio-imaging

University Of California-San Diego, La Jolla CA

Investigators

Abstract

Super-resolution microscopy (SRM) emerged in the past two decades has tremendously impacted life science and medical research. Most of the existing SRM technologies are based on fluorescence which only indicates the present of the labeled targets, limiting their abilities to study complex biological systems where a large number of unknown objects interact with each other simultaneously. Label-free approach, like scattering image, does not rely on fluorescent markers and thus provides unique contrast capabilities for biological imaging. However, achieving sub-100 nm super-resolution (SR) scattering imaging remains a significant challenge. This project aims to develop the first dual-modality SRM that leverages the strengths of both imaging methods by performing SR fluorescent and SR scattering imaging simultaneously at high speed. This new imaging technology is termed as Dual-Modality Localized Plasmonic Structured Illumination Microscopy (DM-LPSIM). As the first technique to achieve video rate SRM for both fluorescence and label-free at 50-nm scale, DM-LPSIM has the potential to change the landscape of bio-imaging for studying many-body bio-interactions. If successfully demonstrated, this new microscopy tool will be made available to local biologists to assist new discoveries in biological and medical research. The educational plan includes graduate and undergraduate students training at the cross-section of optical engineering and biology with emphasis on minority student involvement. The California State Summer School for Mathematics and Science (COSMOS) program and Outreach Program Advancing Learning in STEM (OPALS) will serve as major platforms of outreach to attract more K-12 students to the fields of microscopy and bioimaging. The DM-LPSIM system is essentially a derivative of structured illumination microscopy technique with significantly improved resolving power, relying on engineered illumination patterns beyond the traditional diffraction limit. DM-LPSIM obtains the SR imaging by using a substrate with nanoplasmonic antenna array supporting sub-diffraction-limited localized surface plasmon resonance (LSPR), while also provide high sensitivity SR label-free imaging by taking advantage of the high sensitivity of LSPR with respect to refractive index contrast. Deep learning-based algorithms will be developed to assure high quality SR image reconstruction for both coherent and incoherent light with reduced artifacts. DM-LPSIM represents one of the first SRM techniques for both fluorescence and scattering image at the same time, signifying unique opportunities to investigate nanoscale dynamics in complex cellular activities. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.