About

Guillermo C. Bazan is a Professor Emeritus in the Department of Chemistry & Biochemistry at the University of California, Santa Barbara. He specializes in organic and bioorganic chemistry, inorganic and organometallic chemistry, materials chemistry, molecular design and synthesis, energy, catalysis, green chemistry, devices, assembly, and nanochemistry. Dr. Bazan obtained his B.Sc. from the University of Ottawa and his Ph.D. from MIT, followed by a postdoctoral fellowship at CalTech working with John Bercaw. He joined UCSB in July 1998 as a Professor of organic chemistry and is the Director of the Center for Polymers and Organic Solids. His research program bridges areas of organic chemistry, organometallic chemistry, polymers, and materials science, focusing on the synthesis of organic molecules with architectures that optimize optoelectronic performance, understanding electronic delocalization in solid-state chromophores, developing transmembrane agents for electron transfer, and oligomerization and polymerization reactions of olefins using well-defined organometallic catalysts.

Research topics

• Chemistry
• Physics
• Chemical physics
• Nanotechnology
• Materials science
• Organic chemistry
• Optoelectronics
• Biology
• Optics
• Biochemistry
• Biophysics

Selected publications

• Graphene and amorphous carbon coatings for nitinol cardiovascular stents by direct chemical vapor deposition: A comparative insight

  Materials & Design · 2026-03-17

  articleOpen access

  • Few-layer graphene and amorphous carbon were deposited directly on nitinol cardiovascular stents by ambient-pressure chemical vapor deposition, without interlayers or polymer transfer. • The coatings provided strong corrosion protection, with efficiencies exceeding 80%, while maintaining excellent hemocompatibility. • Amorphous carbon selectively promoted endothelial cell growth while suppressing smooth muscle cell proliferation and inflammatory responses. • This interlayer-free coating strategy offers a simple and multifunctional route for next-generation vascular stent surface engineering. Carbon-based coatings are promising for biomedical implants, including vascular stents, but fabrication on metals often requires adhesion interlayers or polymer-assisted transfer, increasing cost and complexity. Here, we report a simple, ambient-pressure chemical vapor deposition (CVD) process for the direct, interlayer-free growth of two carbon coatings on nitinol (NiTi) stents: few-layer graphene (FLG/NiTi, 170 ± 20 nm) and amorphous carbon (a-C/NiTi, 620 ± 30 nm). Both coatings significantly enhanced corrosion resistance, with protection efficiencies of 83.78% for FLG/NiTi and 89.19% for a-C/NiTi. Vascular cell assays revealed distinct and clinically relevant biological responses. a-C/NiTi promoted vascular endothelial cell (VEC) proliferation (+17.2% at 96 h relative to bare NiTi) while suppressing vascular smooth muscle cell (VSMC) proliferation (−25%), a desirable outcome as excessive VSMC growth drives in-stent restenosis, whereas endothelialization supports vessel healing. In contrast, FLG/NiTi inhibited proliferation of both cell types (>50% reduction for VECs). All samples exhibited excellent hemocompatibility (hemolysis < 0.2%), and a-C/NiTi reduced platelet surface coverage by 30% compared with bare NiTi, beneficial for mitigating thrombosis. Inflammatory assessment further showed a 73% reduction in TNF-α secretion on a-C/NiTi in comparison to bare NiTi. Together, these results demonstrate an interlayer/ polymer-free route to carbon-coated NiTi stents with tunable biological performance.

  PublisherDOI

• Spontaneously N‐Doped Conjugated Polyelectrolyte Coatings Accelerate Electron Uptake in <i>Shewanella Oneidensis</i>

  Advanced Materials · 2026-01-21

  articleSenior authorCorresponding

  Bioelectrochemical systems interconvert electrical and chemical energy using living microorganisms, but their efficiency remains limited by slow electron exchange across abiotic-biotic interfaces. Herein, a spontaneous n-doped water-dispersible conjugated polyelectrolyte (CPE), PNB, is developed. The CPE self-assembles on the surface of Shewanella oneidensis MR-1 to create biocompatible coatings that accelerate inward extracellular electron transfer. PNB is obtained via an aldol condensation reaction and is described by an acceptor-acceptor π-conjugated backbone bearing quaternary ammonium side chains. This molecular architecture enables stable n-doping in aqueous media and a broad reduction potential window. When integrated as a cathodic interlayer, PNB-S. oneidensis biohybrids exhibit a 14-fold enhancement in electron injection and a 4-fold increase in electro-driven succinate production, compared to unmodified cells. Single-cell electrochemical mapping confirms faster, more efficient per-cell electron influx. These findings demonstrate that n-type CPEs can bridge external electrodes with cellular metabolisms, opening a material-based route to high-performance bioelectronic and electrosynthetic systems. By enabling more facile charge transfer between synthetic semiconductors and living catalysts, this work establishes a soft materials-driven framework for designing electronically coupled microbial systems with potential to advance sustainable bioelectronic technologies.

  PublisherDOI

• Conjugated Oligoelectrolytes as Optical Probes

  Accounts of Chemical Research · 2026-02-27

  articleSenior authorCorresponding

  ConspectusOptical probes are essential tools for interrogating biological and chemical systems invisible to the naked eye, providing insights into molecular interactions, protein activity, and cellular trafficking. Conjugated oligoelectrolytes (COEs), an emerging class of optical probes, are synthetic organic amphiphiles defined by a π-conjugated backbone and charged pendant groups. COEs with a linear conjugated structure and charged groups at the two termini can be designed to mimic the molecular dimensions and arrangements of hydrophobic and hydrophilic groups characteristic of lipid bilayers. This design drives their spontaneous intercalation into and prolonged residence within biological lipid bilayer membranes. By tailoring their molecular building blocks, their electronic and photophysical properties as well as their interactions with cells can be readily tuned, positioning COEs as a versatile platform for developing molecular probes for fundamental research and applied bioimaging across a range of biological systems.In this Account, we describe the design strategies elaborated by our group for developing COEs as optical probes, with a focus on their applications and uses in elucidation and tracking of cellular membrane properties. We show that COEs can be used to detect and visualize lipid membranes at multiple length scales, ranging from single microbial cells and exogenously isolated small extracellular vesicles and particles to subcellular organelles and whole cells in live animal models. COEs also function as effective nonlinear optical probes that are applicable in advanced imaging modalities such as two-photon microscopy and stimulated emission depletion microscopy to extract spatiotemporal information at high resolution.We also provide our insights into how COEs can be designed to be functional probes that exhibit predictable photophysical behavior in response to the local molecular and chemical environment. Using fluorescence lifetime imaging microscopy, the time-resolved emission of COEs can be leveraged to provide insight into dynamic processes such as rapid changes in membrane tension and long-term changes in membrane rigidity and composition. We additionally elaborate strategies for modulating interactions with biological membranes, designing membrane-specific probes that respond to specific cellular biophysical parameters, and offer perspectives and opportunities toward developing a new platform for disease detection and diagnosis.

  PublisherDOI

• Single-particle imaging uncovers reverse electron transfer efficiency between Shewanella oneidensis MR-1 and shaped haematite

  Nature Catalysis · 2026-04-28

  article
  PublisherDOI

• Host–Guest Antimicrobial Based on Conjugated Oligoelectrolyte and Cyclodextrin

  Angewandte Chemie International Edition · 2025-05-19 · 8 citations

  article

  Abstract The escalating global threat of antimicrobial resistance necessitates the development of new antimicrobial agents. In this study, we prepared a resveratrol‐derived antimicrobial conjugated oligoelectrolyte (COE) named DY6 to enhance drug‐like properties. While DY6 ’s increased hydrophobicity augmented its antibacterial efficacy, it also induced significant cytotoxicity, highlighting the long‐existing dilemma of amphiphilic antimicrobials. To mitigate this issue, we employed a supramolecular strategy by complexing DY6 with sodium sulfobutyl ether β‐cyclodextrin ( SβCD ), forming the host–guest inclusion complex DY6@SβCD . This complex elevated the half‐maximal inhibitory concentration (IC 50 ) against L929 cells from 9.4 to over 128 µg mL −1 while maintaining a minimum inhibitory concentration (MIC) of 2 µg mL −1 against methicillin‐resistant Staphylococcus aureus (MRSA). NMR and UV–vis spectroscopic analyses confirmed that DY6 ’s aromatic backbone is encapsulated within the hydrophobic cavity of SβCD . Isothermal titration calorimetry revealed that size compatibility and electrostatic interactions are essential for stable complex formation and enhanced biocompatibility. Importantly, DY6@SβCD exhibited no resistance development over 14‐day serial passages against S. aureus , significantly outperforming norfloxacin. In biofilm‐based MRSA‐infected wound and corneal models, DY6@SβCD more effectively reduced bacterial load and inflammation compared to the last‐resort antibiotic vancomycin. These findings demonstrate the potential utility of supramolecular host–guest approach based on COEs to overcome the drug‐resistant challenges.

  PublisherDOI

• Tailoring Lipid Nanoparticle with Ex Situ Incorporated Conjugated Oligoelectrolyte for Enhanced mRNA Delivery Efficiency

  Advanced Healthcare Materials · 2025-03-19 · 1 citations

  articleOpen accessSenior authorCorresponding

  Developing new lipid nanoparticle (LNP) formulations typically involves reconstruction from separate elements followed by rigorous purification steps, contributing to drawn-out drug discovery processes. Membrane-intercalating conjugated oligoelectrolytes (COEs) are water-soluble molecules featuring a conjugated backbone and peripheral ionic groups, specifically designed to spontaneously integrate into lipid bilayers. Herein, an ex situ strategy to "dope" the representative COE-S6 into pre-formed messenger RNA-LNPs (mRNA-LNPs) is presented, exploiting its spontaneous membrane intercalation property through a straightforward add-and-mix procedure. Incorporating 0.2% COE-S6 into mRNA-LNPs relative to lipid content reduced particle size from 84.5 ± 1 to 67.9 ± 0.8 nm, elevated cellular uptake, and improved endosomal escape. These traits culminate in an increase in in cellula transfection from 24.2 ± 1.6% to 98.7 ± 0.6%. When injected intravenously into healthy BALB/c mice, the optimized COE-S6-doped mRNA-LNPs boost in vivo luciferase expression by 1.75-fold. Additionally, COE-S6-doped mRNA-LNPs exhibit fluorogenic properties, enabling intracellular mechanistic studies via confocal microscopy. This simple method enhances the properties of mRNA-LNPs with minimal COE quantities, offering a novel strategy to improve existing LNP formulations and provide optical reporting capabilities, essential for expediting drug discovery and delivery.

  PublisherOA PDFDOI

• Light-triggered molecular mechanotherapy of tumor using membrane-mimicking conjugated oligoelectrolytes

  Science Advances · 2025-08-22 · 4 citations

  articleOpen accessCorresponding

  A class of light-mediated mechanotherapeutic agents was developed on the basis of conjugated oligoelectrolytes (COEs), which mimic the topology of lipid membranes and intrinsically exhibit excellent biocompatibility. Low-dose white light irradiation (20 milliwatts per square centimeter for 10 minutes) substantially decreased the half-maximal inhibitory concentration of the optimized COE against A549 cancer cells from more than 256 to 0.6 micromolar. Typical photodynamic and photothermal effects were not responsible for the potent anticancer efficacy. Biophysical and photophysical experiments using vesicle models revealed that COEs can induce mechanical force likely by molecular conformation change within lipid membranes under light exposure, supporting the mechanotherapeutic mechanism by which COEs after excitation can physically disrupt cell membrane. Investigation of two other COEs with similar spectral properties but different backbone architectures revealed that their mechanotherapeutic efficacy is dependent on molecular topology. These results highlight the potential to develop light-responsive mechanotherapeutic agents based on membrane-mimicking COE platform for cancer treatment.

  PublisherDOI

• Additive Manufacturing of Energy Materials Using Self‐Assembled Graphene Oxide and Printable Resin

  Small · 2025-06-11 · 2 citations

  article

  Abstract A strategy is reported for fabricating 3D‐printed electrodes using self‐assembled graphene oxide (GO) core–shell microspheres as tunable microreactors. This approach enables control over microsphere size and shell thickness via pH adjustment and sonication parameters, yielding either individual conductive particles or interconnected networks suitable for Direct Ink Writing. Following pyrolysis, the resulting hierarchically porous, rigid constructs exhibit surface area of 1000 m 2 g −1 and compressive strengths up to 9.5 MPa – outperforming most 3D‐printed carbon supercapacitor structures in mechanical robustness. Electrochemically, the optimized architecture delivers 125 F g −1 , 1.4 F and 4.7 F cm −3 in 1 m H 2 SO 4 , and maintains &gt;95% of its capacity after 30 000 cycles while preserving structural integrity. This method combines bottom‐up GO self‐assembly with top‐down additive manufacturing to produce mechanically resilient, high‐performance supercapacitor electrodes – bridging nanoscale material design with macroscale energy storage systems engineering.

  PublisherDOI

• Preferential Membrane Remodeling on Curved Biointerfaces Induced by Conjugated Oligoelectrolyte

  Advanced Materials Interfaces · 2025-04-08 · 1 citations

  articleOpen accessCorresponding

  Abstract Conjugated oligoelectrolytes (COEs) spontaneously intercalate into and modulate lipid membranes thanks to their hydrophobic backbone and hydrophilic ionic termini, enabling applications in biosensing, fluorescence imaging, antimicrobial therapy, and bioelectrochemical devices. While COE‐membrane interactions are fundamental to their functionality, the intimate details of how COEs interact with membranes remain underexplored, particularly the influence of membrane shape–a defining feature of subcellular organelles that significantly influences the spatial organization and behavior of membrane‐associated molecules. This study introduces a curved biointerface comprising vertical nanostructure arrays and supported lipid bilayers (SLBs) to investigate how membrane shape affects the COE‐bilayer interaction. The curved SLB, following the predefined shapes of the nanobar array, mimics the natural curvature of subcellular membranes. Interestingly, the COE intercalation preferentially induces distinct membrane remodeling patterns from curved regions, i.e., tubes and patches linking to the nanobars, but not the adjacent flat membranes. The pattern morphology and stability alter with COE concentration changes and are sensitive to lipid composition. COE species with higher hydrophobicity provide more persistent remodeling over time. This study highlights the significance of membrane shape in COE‐membrane interactions and validates the nanobar‐curved membrane biointerface as a powerful platform to uncover mechanisms of membrane intercalation and modulation by membrane‐specific compounds.

  PublisherDOI

• Mechanosensitive Conjugated Oligoelectrolytes for Visualizing Temporal Changes in Live Cells

  Angewandte Chemie · 2025-05-06

  articleSenior author

  Abstract Membrane‐intercalating conjugated oligoelectrolytes (COEs) are lipid‐bilayer‐spanning molecules that serve as fluorescent dyes for bioimaging. However, COE emission has thus far only been capable of visualizing dye location and their preferential accumulation in different membrane‐bound intracellular compartments. Herein, we report the first example of environmentally sensitive COEs for visualizing temporal changes in live cells, providing information on the physical properties of intracellular lipid bilayer membranes. The new COE‐BY series is designed around a BODIPY central unit with a membrane‐spanning topology and six cationic pendant groups ensuring solubility in aqueous media. These reporters feature high two‐photon absorption cross section, NIR‐II excitation capabilities under multiphoton excitation, and high dye brightness; all highly desirable photophysical features for bioimaging. The emission lifetime of the probes was sensitive to changes to both the lipid composition of model vesicle systems and membrane tension within cells, induced by either mechanical or osmotic stress. Using two‐photon fluorescence lifetime imaging microscopy, it is possible to use the most efficient emitter, namely, COE‐BYPhOC4 , to image changes in the mechanical properties of intracellular membranes. We show that these COEs remain stably vesicle‐bound within the endolysosomal pathway over extended periods, allowing for long‐term monitoring of the associated biophysical changes of these vesicles over time.

  PublisherDOI

Recent grants

• Conjugated Polyelectrolytes for Optoelectronic Applications

  NSF · $405k · 2010–2013

• Conjugated Polyelectrolytes for Optoelectronic Applications

  NSF · $345k · 2006–2010

• Design and Processing of Conjugated Polymers with High Charge Carrier Mobilities

  NSF · $390k · 2014–2019

Frequent coauthors

• Thuc‐Quyen Nguyen

  University of California, Santa Barbara

  243 shared

• Alan J. Heeger

  141 shared

• Glenn P. Bartholomew

  90 shared

• Cheng‐Kang Mai

  Harbin Institute of Technology

  83 shared

• Samantha R. McCuskey

  National University of Singapore

  79 shared

• Ming Wang

  North China Institute of Science and Technology

  77 shared

• Michael J. Ford

  Lawrence Livermore National Laboratory

  75 shared

• Guang Wu

  University of California, Santa Barbara

  74 shared

Education

• PhD, Chemistry

  Massachusetts Institute of Technology

  1990