Porous polymer-derived membranes are useful for applications ranging from filtration and separation technologies to energy storage and conversion. Combining block copolymer (BCP) self-assembly with the industrially scalable, non-equilibrium phase inversion technique (SNIPS) yields membranes comprising periodically ordered top surface structures supported by asymmetric, hierarchical substructures that together overcome performance tradeoffs typically faced by materials derived from equilibrium approaches. This review first reports on recent advances in understanding the top surface structural evolution of a model SNIPS-derived system during standard membrane formation. Subsequently, the application of SNIPS to multicomponent systems is described, enabling pore size modulation, chemical modification, and transformation to non-polymeric materials classes without compromising the structural features that define SNIPS membranes. Perspectives on future directions of both single-component and multicomponent membrane materials are provided. This points to a rich and fertile ground for the study of fundamental as well as applied problems using non-equilibrium-derived asymmetric porous materials with tunable chemistry, composition, and structure.
Fluorescent
labeling of cellular substructures is commonly performed
using antibody–organic dye conjugates. Organic dyes do not
exhibit ideal optical properties in terms of brightness and photostability,
however, in particular when it comes to advanced optical super-resolution
microscopy (SRM) applications. Here, we demonstrate the efficient
conjugation of widely available secondary antibodies and cationic
species to ultrasmall (sub-10 nm) fluorescent silica corepoly(ethylene
glycol) shell (core–shell) aluminosilicate nanoparticles (aC′
dots) encapsulating different color dyes for specific targeting and
high-quality fluorescence imaging of structures of the cytoskeleton
(tubulin and actin) and nucleus, respectively. We show that the different
color aC′ dots provide enhanced brightness and photostability
relative to their parent dyes. As recently discovered, we further
demonstrate that they exhibit photo-induced blinking with low ON–OFF
duty cycles enabling optical SRM, for example, in the form of stochastic
optical reconstruction microscopy (STORM), without the need for complex
imaging setups or cocktails. After carefully optimizing Ab–aC′
dot conjugation as well as cell structure labeling protocols in fixed
and permeabilized HeLa and MDA-MB-231 cells, we demonstrate three-color
STORM and exemplify improved resolution compared to standard antibody–dye
conjugates. This work paves the way to next-generation multifunctional
optical probes based on ultrasmall silica nanoparticle platforms for
advanced applications in bioimaging, nanomedicine, and beyond.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.