Research

From photochemistry to microbial function.

Our laboratory investigates how light-generated reactive oxygen species interact with microorganisms, biological interfaces, and engineered materials. We combine mechanistic photochemistry with quantitative microbiology and imaging to understand oxidative stress and develop new antimicrobial strategies.

Research directions

Four interconnected areas.

Each research direction addresses a different scale of the same central problem: how reactive oxygen species can be generated, controlled, measured, and used to influence microbial systems.

01

Oxidative stress & single-cell biology

Understanding heterogeneous bacterial responses at the level of individual cells.

02

Antimicrobial photodynamic therapy

Connecting photosensitizer photochemistry with microbial inactivation mechanisms.

03

Bacteriophages & photochemistry

Combining biological targeting with photochemical generation of oxidative stress.

04

Photoactive materials

Developing reusable light-responsive platforms, including 3D-printed systems.

Research program

Current research themes

01 / SINGLE-CELL BIOLOGY

Bacterial oxidative stress & phenotypic heterogeneity

Schematic showing a bacterial population under oxidative stress, single-cell imaging, and heterogeneous cell responses.
Conceptual overview of how oxidative stress can generate diverse outcomes across individual bacterial cells.

Genetically similar bacteria can respond very differently to the same oxidative challenge. Population-level measurements often hide this variability, making it difficult to understand why some cells are rapidly damaged while others persist.

We use fluorescence microscopy and quantitative image analysis to follow individual cells during photodynamic treatment. These experiments allow us to measure the timing and distribution of membrane permeabilization, oxidative damage, and survival-related phenotypes across bacterial populations.

Central question What cellular and physiological factors determine why individual bacteria display different sensitivities to oxidative stress?

Single-cell fluorescence microscopy

Time-resolved imaging of bacterial viability, membrane integrity, and stress responses.

Quantitative image analysis

Extraction of cell-level kinetic parameters from microscopy datasets.

Growth-state comparisons

Analysis of how physiological state changes the distribution of oxidative-stress responses.

Population vs. single-cell measurements

Connecting bulk antimicrobial outcomes with cell-to-cell heterogeneity.

02 / PHOTODYNAMIC THERAPY

Antimicrobial photodynamic therapy

Schematic showing photosensitizer, light, oxygen, reactive oxygen species, and bacterial damage in antimicrobial photodynamic therapy.
Simplified mechanism of antimicrobial photodynamic therapy: a photosensitizer plus light and oxygen produces reactive oxygen species that damage bacteria.

Antimicrobial photodynamic therapy uses a photosensitizer, light, and molecular oxygen to generate reactive oxygen species capable of damaging microbial cells. Our work focuses on understanding the photochemical and biological factors that determine treatment efficacy.

We evaluate photosensitizer performance using complementary spectroscopic, chemical, microbiological, and imaging approaches. A major goal is to distinguish improved light harvesting from changes in intrinsic reactive-oxygen generation and to connect these photophysical properties with biological activity.

Central question How do photosensitizer structure, localization, light absorption, and reactive oxygen species production translate into microbial inactivation?

Photosensitizer characterization

Absorption, emission, photostability, and light-harvesting measurements.

Reactive oxygen species assays

Optical and chemical probes for evaluating photosensitized oxidation.

Time-kill experiments

Quantitative measurements of bacterial inactivation as a function of light dose and treatment conditions.

Mechanistic microscopy

Real-time visualization of cell damage during light exposure.

03 / PHAGE PHOTOCHEMISTRY

Bacteriophages as targeted photochemical platforms

Schematic showing a bacteriophage selectively binding a target bacterium, light activation, localized reactive oxygen species, and selective bacterial damage.
Phage-assisted targeting strategy in which bacteriophage specificity is combined with light-activated oxidative stress.

Bacteriophages provide highly specific recognition of bacterial hosts. We are exploring ways to combine that biological specificity with photosensitizer chemistry so that light-generated oxidative stress can be delivered more selectively.

This work includes studies of photosensitizer–phage association and conjugation, preservation of phage infectivity after chemical modification, and the effect of oxidative stress on phage–host interactions.

Central question Can bacteriophage specificity be coupled to photochemical reactivity without compromising the biological function required for host recognition and infection?

Phage labeling chemistry

Strategies for attaching photosensitizers to phage capsids while minimizing disruption of infective structures.

Phage purification

Buffer exchange, centrifugal filtration, and characterization of modified phage preparations.

Host–phage kinetics

Monitoring bacterial growth, lysis, and infection dynamics under oxidative conditions.

Fluorescence-based infection studies

Using optical reporters to probe membrane and oxidative changes during infection.

04 / PHOTOACTIVE MATERIALS

Photoactive polymers & 3D-printed antimicrobial materials

Schematic showing photosensitizer-loaded filament, 3D printing, a printed device, light activation, and antimicrobial effect.
Workflow for producing photoactive 3D-printed antimicrobial materials from photosensitizer-loaded filament to light-activated application.

We incorporate photosensitizers into polymeric materials to create reusable surfaces and devices that respond to visible light. Additive manufacturing allows us to control geometry, composition, and application-specific design while retaining photochemical function.

Current work includes dye-loaded PLA systems produced by melt processing and 3D printing. We evaluate their optical properties, photosensitizer release, photostability, recyclability, and light-dependent antimicrobial performance.

Central question How can molecular photosensitizers be integrated into functional materials while preserving the optical and chemical behavior needed for antimicrobial activity?

Polymer processing

Photosensitizer incorporation by melt blending, filament extrusion, and 3D printing.

Optical characterization

Absorption and fluorescence measurements of photosensitizer-loaded materials.

Release kinetics

Quantitative analysis of photosensitizer release from printed materials into aqueous media.

Antimicrobial performance

Light-dependent inactivation assays using printed photoactive devices and surfaces.

Cross-cutting capabilities

Methods that connect our projects.

The lab is built around combinations of chemistry, quantitative imaging, microbiology, and materials characterization rather than a single experimental platform.

Photochemistry

Light-driven reactions, photosensitizers, and reactive oxygen species generation.

Spectroscopy

Absorption, fluorescence, and quantitative optical characterization.

Fluorescence microscopy

Live-cell and time-resolved imaging at the single-cell level.

Quantitative microbiology

Culture-based viability, growth kinetics, and antimicrobial response measurements.

Additive manufacturing

Filament preparation and 3D printing of functional photoactive materials.

Data analysis

Kinetic modeling, image quantification, and statistical analysis across biological scales.

Work with us

Interested in interdisciplinary photochemical research?

Our projects provide opportunities for undergraduate and graduate students to work across chemistry, microbiology, microscopy, quantitative analysis, and materials science.

Meet the group