Ke Xu Group

We are an interdisciplinary lab that develops new physicochemical tools to interrogate biological, chemical, and materials systems at the nanoscale with extraordinary resolution, sensitivity, and functionality. To do so, we take a multidimensional approach that integrates advanced microscopy, spectroscopy, cell biology, and nanotechnology.


Why is an ER tubule like an ER sheet?

STORM unveils a striking structural dichotomy of ER tubules in mammalian cells, and fast multicolor imaging shows how the two distinct tubule forms dynamically interconvert in the living cell. [Link]

Congratulations to Bowen and the team! Another tour de force!

Dynamic blistering of graphene

Another fascinating discovery enabled by interference reflection microscopy (IRM). Substrate-supported graphene blisters dynamically in acids -and behaves as a semipermeable membrane! [Link] [Cover]

Congratulations to Yunqi and the team!

A key null result

By showing no enhanced diffusion in enzymatic reactions, we also define the achievable precision for diffusivity from single-molecule displacement statistics. [Link]

Congratulations to Alex and the team!

t-ERGIC: A SURF4 expressway for ER-to-Golgi transport

Following an unexpected discovery of tubular ERGIC, we elucidate a fascinating system that selectively expedites the ER-to-Golgi transport of SURF4 cargos. [Link]

Congratulate Rui for leading this tour de force and Kun and Bowen for the teamwork. I feel we all become better biologists through this journey!

New strategy for STORM dyes

With a very chemistry title, our new paper [Link] introduces a new strategy for high-performance STORM dyes. Highly recommended to anyone trying to achieve optimal results beyond the good old red-excitation window.

Congratulations, Bowen and Michael! Thanks go to our collaborators at Biotium.

Single molecules are your quanta

Our Perspective article in ACS Nano [Link] reflects on the underlying philosophy of how diffraction-unlimited pictures containing rich spatial and functional information emerge through the local accumulation of single-molecule measurements. This is an exciting field, and we hope we achieved our goal of making it understandable to all.

Congratulations to Limin and Kun. We thank all past and current lab members for contributing to related work!

A new approach for fast spectral microscopy

Fed up with the challenges of dispersing the emission spectrum for spectral microscopy? See how we achieved highly multiplexed fluorescence imaging for both multi-targets and biosensing by scanning the excitation wavelength instead! [Link]

Congratulations, Kun, Rui, and Limin!

Cell biology & microscopy

See our new BioRxiv posts, focusing on membrane-trafficking biology [Link] and spectral microscopy [Link], respectively. More details to follow after publication.

Congratulations, Rui and Kun, for respectively leading these two remarkable studies!

Facile chlorination of graphene

Electrochemical functionalization of graphene in the aqueous phase: See how we moved from a pseudohalogen to real halogens, including the table salt! [Link]

Congratulations, Wan and Yunqi!

A multidimensional single-molecule & super-resolution approach for membrane diffusion

By integrating SMdM (single-molecule displacement/diffusivity mapping) with spectrally resolved SMLM and 3D-SMLM, we resolve and differentiate between nanoscale diffusional heterogeneities in live-cell membranes. See also our new principal-direction SMdM (pSMdM) analysis! [Link]

Congratulations, Rui and Kun!

Graphene-enabled, spatially controlled electroporation of adherent cells for live-cell super-resolution microscopy

Another remarkable integration of graphene and super-resolution microscopy –with unique spatiotemporal controls, too! [Link]

Congratulations, Seonah, Wan, and Meg!

Single-molecule displacement mapping unveils nanoscale heterogeneities and charge effects in intracellular diffusivity

We extend super-resolution microscopy to the new dimensions of single-molecule velocity and diffusivity. We thus unveil rich, nanoscale heterogeneities and charge effects in intracellular diffusion. Intriguingly, we find the possession of positive, but not negative, net charges drastically impedes diffusion –why? Read our paper to find out! [Link]

Congratulations, Limin, Kun, Rui, and Wan! Another milestone!

Azidated graphene: direct azidation from monolayers, click chemistry, and bulk production from graphite

We report direct azidation and subsequent click chemistry of the graphene basal plane through a facile electrochemical strategy. [Link]

Congratulations to Wan and Yunqi! Great chemistry!

Super-resolution microscopy: a new angle

Our collaboration with Xiang Zhang Lab created oblique-plane STORM, a light-sheet super-resolution method that enables direct cross-sectional imaging through up to 66 µm deep into tissues and small intact animals. [Link]

Congratulations to Jeongmin, Michal, Seonah, and all collaborators!

Tailor-made switchable solvatochromic probes for live-cell superresolution imaging of plasma membrane organization

Our collaboration with Andrey Klymchenko Lab led to NR4A, a solvatochromic probe optimized for the spectrally resolved, functional super-resolution microscopy of live-cell plasma membranes. [Link]

Congratulations to Seonah and our collaborators!

Graphene photochemistry and spatial heterogeneities in reactivity

Interference reflection microscopy unveils a photochemistry mechanism and rich spatial heterogeneities for the reaction of monolayer graphene with aryl diazonium. [Link]

Congratulations to Yunqi, Wan, Michal, Bowen, and our STROBE collaborators, Liang-Chun Lin and Markus Raschke!

Congratulations to Seonah, Shirley, Zhiheng (and Sam)!

Congratulations to Seonah, Shirley, and Zhiheng for their graduation, and also to Sam for completing his Ph.D. requirement earlier!

We are proud of you and will miss you all!

Multidimensional super-resolution microscopy through machine learning

Machine learning (magically) resolves both the colors and the axial positions of unmodified single-molecule images for STORM! [Link]

Great job, Taehwan and Seonah!

Optical microscopy unveils rapid, reversible electrochemical oxidation and reduction of graphene

Another demonstration of the power of optical microscopy for chemical reactions, in this case for electrochemistry -and graphene is reversibly oxidized and reduced! [Link]

Congratulations to Wan and Michal!

Ke received NIH Director's New Innovator Award!

Of sperms -and vesicles

See our collaborative work with the Lishko Lab and the Schekman Lab, resolving the mysteries of sperm ion channels [Link] and the large COPII-coated vesicles [Link], respectively.

Congratulations, Sam, for both papers!

A conserved, periodic nanoscale scaffold and ruler of the neural stem cell lineage

Our super-resolution work reveals a highly conserved one-dimensional periodic cytoskeletal motif in neural stem cells and derivatives, and shows that this periodic scaffold guides intercellular interactions as a nanoscale ruler. [Link]

Congratulations, Meg and Rui! What a tour de force!

Super-resolution microscopy of graphene nanoribbons

Our collaboration work with the Fischer Lab enables super-resolution microscopy for graphene nanoribbons. [Link]

Congratulations to Meg and our collaborators!

Congratulations to Meg, Michal, Yennie, and Manni!

Congratulations to Meg and Michal for becoming the first graduated Ph.D.'s from the Xu Lab!

Congratulations also to Yennie and Manni's graduation!

We are so proud of you and will miss you all!

Functional super-resolution microscopy for surface chemistry

Our new work in Nature Comm. reveals the fascinating nanoscale structure and composition of surface adlayers. [Link]

See also our other new work in ACS Nano and bioRxiv.

Congratulations to Limin, Michal, Sam, and all!

Our article in Accounts of Chemical Research

We summarize the rationale, design, and results of our recent efforts toward the integration of single-molecule spectroscopy with super-resolution microscopy. [Link]

Thanks go to all past and current lab members, who made this possible.

Resolving the native ultrastructure of the erythrocyte cytoskeleton

Super-resolution microscopy resolves the cytoskeletal meshwork of intact erythrocytes and reveals an 80 nm junction-to-junction distance. [Link]

Congratulations Leiting, Rui, and Wan!

Our article in JACS

Our article "Spatially resolved in situ reaction dynamics of graphene via optical microscopy" has been published in Journal of the American Chemical Society!

Congratulations Michal, Yunqi, and Wan!

Our article in Chemical Reviews

Our article "Correlative Super-Resolution Microscopy: New Dimensions and New Opportunities" has been published in Chemical Reviews!

Congratulations Meg, Michal, Doory, and Wan! -Great way to start a new year!

Ke received the Packard Fellowship for Science and Engineering!

Congratulations on your recent awards, Ke!

Ke named one of the Talented 12 by Chemical & Engineering News!

Ke received NSF CAREER Award and Beckman Young Investigators Award!

Our new work in Nano Letters!

Our new paper, "Direct Optical Visualization of Graphene and Its Nanoscale Defects on Transparent Substrates", has been published in Nano Letters! [Link]

Congratulations Wan, Seonah, and Michal!

Ke named a Sloan Research Fellow!

Ke has received the Sloan Research Fellowship!

Congratulations Ke!

Our new paper in Nature Methods!

Our new paper, “Ultrahigh-throughput single-molecule spectroscopy and spectrally resolved super-resolution microscopy”, has been published in Nature Methods! [Link]

See also news release by LBL: [Link]

Congratulations Zhengyang, Sam, Meg, and Wan!

Our first paper published in Nature Communications!

Our first paper, "Graphene-enabled electron microscopy and correlated super-resolution microscopy of wet cells," has been published in Nature Communications! [Link]

Congratulations Michal, Meg, and Seonah!