School of Humanities and Sciences
Showing 11-20 of 57 Results
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Leah B. Bushin
Assistant Professor of Chemistry
BioLeah Bushin is a chemical biologist and natural products chemist working at the interface of primary and secondary metabolism and leverages these insights to discover and produce novel natural products.
The Bushin research group will investigate novel metabolic pathways, enzymes, and bioactive molecules across all kingdoms of life, intending to repurpose them to address challenges in human health and environmental sustainability. Current efforts will primarily center on developing strategies for the efficient microbial production of compounds and materials at scale, as well as high-throughput approaches for engineering enzymes to perform synthetic reactions. More broadly, as the group designs and refines bioproduction platforms, they hope to deepen their fundamental understanding of cellular metabolism. With genome sequencing revealing an immense reservoir of untapped biosynthetic potential, their work aims to uncover and harness nature’s chemical diversity for drug discovery and synthetic derivatization. -
Lynette Cegelski
Monroe E. Spaght Professor of Chemistry and Professor, by courtesy, of Chemical Engineering
Current Research and Scholarly InterestsResearch in the Cegelski laboratory is driven by the need to uncover and define the chemistry that underlies outstanding challenges in human health, the environment, and sustainability. Beyond discovery, we use chemistry as a tool to innovate and create solutions to these pressing problems. The laboratory is highly interdisciplinary, designing experimental approaches to understand how complex biological systems are built, organized, and controlled, and then perturb and influence assembly processes. The lab develops new methods and uniquely leverages: (1) small molecules in new biochemical assay development, chemical genetics approaches, and therapeutic discovery in infectious diseases, (2) fluorescence and electron microscopy coupled to analytical HPLC, mass spectrometry, and complementary biochemical techniques, and (3) spectroscopy, particularly solid-state NMR, to uncover new “dark matter” and define chemistry in insoluble, heterogeneous and complex assemblies relevant to human health, plants, and the ocean.
Long-standing efforts in the laboratory focus on defining mechanisms underlying bacterial biofilm formation and identifying new antibiotic and anti-virulence strategies, including advancing therapeutic candidates for the most difficult-to-treat infections. Through these efforts, we uncovered a new chemical structure in nature: phosphoethanolamine (pEtN) cellulose. Cellulose is the most abundant biopolymer on earth and this discovery provided the first experimental validation of a naturally produced chemically modified cellulose. We are developing alternatively modified celluloses and polysaccharides and advancing new solutions for ecofriendly, sustainably sourced, and recyclable materials. Collectively, our projects span disciplines from molecular structure and assembly chemistry to living microbial communities and natural marine systems, while aiming to translate fundamental discoveries into therapeutic and materials solutions. -
James K. Chen
Jauch Professor and Professor of Chemical and Systems Biology, of Developmental Biology and of Chemistry
Current Research and Scholarly InterestsOur laboratory combines chemistry and developmental biology to investigate the molecular events that regulate embryonic patterning, tissue regeneration, and tumorigenesis. We are currently using genetic and small-molecule approaches to study the molecular mechanisms of Hedgehog signaling, and we are developing chemical technologies to perturb and observe the genetic programs that underlie vertebrate development.
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Christopher Chidsey
Associate Professor of Chemistry, Emeritus
Current Research and Scholarly InterestsThe Chidsey group research interest is to build the chemical base for molecular electronics. To accomplish this, we synthesize the molecular and nanoscopic systems, build the analytical tools and develop the theoretical understanding with which to study electron transfer between electrodes and among redox species through insulating molecular bridges
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James Collman
George A. and Hilda M. Daubert Professor of Chemistry, Emeritus
BioProfessor Emeritus James Collman has made landmark contributions to inorganic chemistry, metal ion biochemistry, homogeneous catalysis, and transition metal organometallic chemistry. He pioneered numerous now-popular research tools to reveal key structural and functional details of metalloenzymes essential to respiration and energy, and hemoglobin and myoglobin, essential to oxygen transport in the blood.
Born 1932 in Beatrice, Nebraska, James P. Collman studied chemistry at U. Nebraska–Lincoln (B.S. 1954, M.S. 1956). His doctoral work at U. Illinois at Urbana-Champaign (Ph.D., 1958) focused on Grignard reagents. As a faculty member at U. North Carolina, he demonstrated aromatic reactivity in metal acetylacetonates, and he developed metal complexes that hydrolyze peptide bonds under physiological conditions. He came to Stanford University as Professor of Chemistry in 1967. Among many honors, Prof. Collman’s was elected to the National academy of Sciences in 1975, and named California Scientist of the Year in 1983.
At Stanford, Prof. Collman invented a new paradigm for studying biological systems using functional synthetic analogs of metal-containing enzyme systems, free from the protein coatings that can affect metalloprotein chemical properties. This strategy allowed him to elucidate the intrinsic reactivity of the metal center as well as the effects of protein-metal interactions on biological function.
One focal point of this research has involved heme-proteins such as the oxygen (O2) carrier hemoglobin (Hb), and the O2-storing protein myoglobin (Mb). Prof. Collman was the first to prepare and characterize stable, functional analogues of the Hb and Mb active sites, which contain an iron derivative of the large flat “porphyrin” ligand. In his “picket fence” porphyrin, groups installed on the periphery block side reactions, which would otherwise degrade the structure. This protected iron complex manifests the unique magnetic, spectroscopic and structural characteristics of the O2-binding Hb and Mb sites, and exhibits very similar O2-binding affinities.
The Collman Group also prepared functional mimics of the O2-binding/reducing site in a key respiration enzyme, cytochrome c oxidase, CcO, which converts O2 to H2O during biosynthesis of the energy storage molecule ATP. This enzyme must be very selective: partial O2 reduction products are toxic. Prof. Collman invented a powerful synthetic strategy to create analogs of the CcO active site and applied novel electrochemical techniques to demonstrate that these models catalyze the reduction of O2 to water without producing toxic partially-reduced species. He was able to mimic slow, rate-limiting electron delivery by attaching his CcO model to a liquid-crystalline membrane using “click chemistry.” He demonstrated that hydrogen sulfide molecules and heterocycles reversibly bind to the metal centers at CcO’s active site, connecting a synthetic enzyme model to simple molecules that reversibly inhibit respiration. These respiration inhibitors exhibit physiological properties, affecting blood clotting and controlling the effects of the hormone, nitric oxide, NO.
In addition, Prof. Collman performed fundamental studies of organometallic reactions. He also prepared and characterized homodinuclear and heterodinuclear complexes having metal-metal multiple bonds, and made the first measurements of the rotational barriers found in multiple metal-metal bonds.
Prof. Collman’s impactful textbook “Principles and Applications of Organotransition Metal Chemistry” has seen multiple editions. His book “Naturally Dangerous: Surprising Facts About Food, Health, and the Environment” explains the science behind everyday life, and received favorable reviews in Nature and The Washington Post. -
Bianxiao Cui
Job and Gertrud Tamaki Professor of Chemistry
Current Research and Scholarly InterestsOur objective is to develop new biophysical methods to advance current understandings of cellular machinery in the complicated environment of living cells. Currently, we are focusing on four research areas: (1) Membrane curvature at the nano-bio interface; (2) Nanoelectrode arrays (NEAs) for scalable intracellular electrophysiology; (3) Electrochromic optical recording (ECORE) for neuroscience; and (4) Optical control of neurotrophin receptor tyrosine kinases.
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Yi Cui
Fortinet Founders Professor, Professor of Materials Science and Engineering, of Energy Science and Engineering, of Photon Science, Senior Fellow at Woods, at Precourt and Professor, by courtesy, of Chemistry
BioCui studies fundamentals and applications of nanomaterials and develops tools for their understanding. Research Interests: nanotechnology, batteries, electrocatalysis, wearables, 2D materials, environmental technology (water, air, soil), cryogenic electron microscopy.
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Hongjie Dai
The J.G. Jackson and C.J. Wood Professor of Chemistry, Emeritus
BioProfessor Dai’s research spans chemistry, physics, and materials and biomedical sciences, leading to materials with properties useful in electronics, energy storage and biomedicine. Recent developments include near-infrared-II fluorescence imaging, ultra-sensitive diagnostic assays, a fast-charging aluminum battery and inexpensive electrocatalysts that split water into oxygen and hydrogen fuels.
Born in 1966 in Shaoyang, China, Hongjie Dai began his formal studies in physics at Tsinghua U. (B.S. 1989) and applied sciences at Columbia U. (M.S. 1991). He obtained his Ph.D. from Harvard U and performed postdoctoral research with Dr. Richard Smalley. He joined the Stanford faculty in 1997, and in 2007 was named Jackson–Wood Professor of Chemistry. Among many awards, he has been recognized with the ACS Pure Chemistry Award, APS McGroddy Prize for New Materials, Julius Springer Prize for Applied Physics and Materials Research Society Mid-Career Award. He has been elected to the American Academy of Arts and Sciences, National Academy of Sciences (NAS), National Academy of Medicine (NAM) and Foreign Member of Chinese Academy of Sciences.
The Dai Laboratory has advanced the synthesis and basic understanding of carbon nanomaterials and applications in nanoelectronics, nanomedicine, energy storage and electrocatalysis.
Nanomaterials
The Dai Lab pioneered some of the now-widespread uses of chemical vapor deposition for carbon nanotube (CNT) growth, including vertically aligned nanotubes and patterned growth of single-walled CNTs on wafer substrates, facilitating fundamental studies of their intrinsic properties. The group developed the synthesis of graphene nanoribbons, and of nanocrystals and nanoparticles on CNTs and graphene with controlled degrees of oxidation, producing a class of strongly coupled hybrid materials with advanced properties for electrochemistry, electrocatalysis and photocatalysis. The lab’s synthesis of a novel plasmonic gold film has enhanced near-infrared fluorescence up to 100-fold, enabling ultra-sensitive assays of disease biomarkers.
Nanoscale Physics and Electronics
High quality nanotubes from his group’s synthesis are widely used to investigate the electrical, mechanical, optical, electro-mechanical and thermal properties of quasi-one-dimensional systems. Lab members have studied ballistic electron transport in nanotubes and demonstrated nanotube-based nanosensors, Pd ohmic contacts and ballistic field effect transistors with integrated high-kappa dielectrics.
Nanomedicine and NIR-II Imaging
Advancing biological research with CNTs and nano-graphene, group members have developed π–π stacking non-covalent functionalization chemistry, molecular cellular delivery (drugs, proteins and siRNA), in vivo anti-cancer drug delivery and in vivo photothermal ablation of cancer. Using nanotubes as novel contrast agents, lab collaborations have developed in vitro and in vivo Raman, photoacoustic and fluorescence imaging. Lab members have exploited the physics of reduced light scattering in the near-infrared-II (1000-1700nm) window and pioneered NIR-II fluorescence imaging to increase tissue penetration depth in vivo. Video-rate NIR-II imaging can measure blood flow in single vessels in real time. The lab has developed novel NIR-II fluorescence agents, including CNTs, quantum dots, conjugated polymers and small organic dyes with promise for clinical translation.
Electrocatalysis and Batteries
The Dai group’s nanocarbon–inorganic particle hybrid materials have opened new directions in energy research. Advances include electrocatalysts for oxygen reduction and water splitting catalysts including NiFe layered-double-hydroxide for oxygen evolution. Recently, the group also demonstrated an aluminum ion battery with graphite cathodes and ionic liquid electrolytes, a substantial breakthrough in battery science. -
Laura M.K. Dassama
Assistant Professor of Chemistry and of Microbiology and Immunology
BioLaura Dassama is a chemical biologist who uses principles from chemistry and physics to understand complex biological phenomena. Her group’s primary goal is to use detailed understanding of the factors that enable interactions between biological molecules to provide insights that allow functional control of those molecules. Her research projects aim to 1) discover the drivers of biomolecular interactions and 2) leverage that information to modulate disease relevant proteins.
