Resolution-enhanced multifocal structured illumination microscopy using fluorescence fluctuations and Fourier ptychography scheme

This is the authors' abstract. We don't add key points for this paper.

Multifocal structured illumination microscopy (MSIM) provides a twofold resolution enhancement over the optical diffraction limit at depths of up to 50 μm in samples. This is achieved through sparse multifocal excitation patterns and digital image post-processing, making MSIM a highly advantageous technique for the three-dimensional super-resolution (SR) imaging of thick specimens. However, the spatial resolution of MSIM is inherently constrained by its underlying imaging principles. This paper presents what we believe to be a novel method that integrates SR optical fluctuation imaging based on Fourier ptychography and deconvolution (SFPD) with MSIM, termed SFPD-MSIM. Using photoblinking InP/ZnSe/ZnS core-shell quantum dot fluorescent probes for sample labeling, we demonstrate that, compared to wide-field imaging microscopy, SFPD-MSIM achieves fourfold resolution improvement. Additionally, it substantially reduces the image-acquisition time while preserving the structural integrity of the original samples. This advancement marks a major step forward in MSIM technology, providing a powerful tool for detailed structural analysis of complex and thick biological specimens.