Premium
Addressing Particle Compositional Heterogeneities in Super‐Resolution‐Enhanced Live‐Cell Ratiometric pH Sensing with Ultrasmall Fluorescent Core–Shell Aluminosilicate Nanoparticles
Author(s) -
Lee Rachel,
Erstling Jacob A.,
Hinckley Joshua A.,
Chapman Dana V.,
Wiesner Ulrich B.
Publication year - 2021
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202106144
Subject(s) - materials science , fluorescence , total internal reflection fluorescence microscope , nanoparticle , particle (ecology) , microscopy , nanotechnology , fluorescence microscope , superresolution , resolution (logic) , optics , computer science , physics , oceanography , geology , artificial intelligence , image (mathematics)
The interrogation of metabolic parameters like pH in live‐cell experiments using optical super‐resolution microscopy (SRM) remains challenging. This is due to a paucity of appropriate metabolic probes enabling live‐cell SRM‐based sensing. Here, ultrasmall fluorescent core–shell aluminosilicate nanoparticle sensors (FAM–ATTO647N aC′ dots) that covalently encapsulate a reference dye (ATTO647N) in the core and a pH‐sensing moiety (FAM) in the shell are introduced. Only the reference dye exhibits optical blinking enabling live‐cell stochastic optical reconstruction microscopy (STORM). Using data from cells incubated for 60 min with FAM–ATTO647N aC′ dots, pixelated information from total internal reflection fluorescence (TIRF) microscopy‐based ratiometric sensing can be combined with that from STORM‐based localizations via the blinking reference dye in order to enhance the resolution of ratiometric pH sensor maps beyond the optical diffraction limit. A nearest‐neighbor interpolation methodology is developed to quantitatively address particle compositional heterogeneity as determined by separate single‐particle fluorescence imaging methods. When combined with STORM‐based estimates of the number of particles per vesicle, vesicle size, and vesicular motion as a whole, this analysis provides detailed live‐cell spatial and functional information, paving the way to a comprehensive mapping and understanding of the spatiotemporal evolution of nanoparticle processing by cells important, e.g., for applications in nanomedicine.