CAREER: Bottom-Up UV Approach for Real-Time Investigation and Control of Microbial Fouling at the Attachment Interface

Biofilms are thin layers of bacteria that can stick to wet surfaces. They can cause serious problems in hospitals, water systems, ships, and food production. Current methods to stop biofilm growth can involve toxic chemicals, special coatings, or intensive scrubbing. These methods are costly, short-lived, and detrimental to the environment. This CAREER project will take a new approach. It will fabricate surfaces that emit UV light from within the material itself, so that bacteria will not be able to attach to the surface in the first place. The research team at the University of Massachusetts Amherst will use a novel UV-emitting glass to observe exactly how bacteria respond to light at a surface. These findings will guide the expansion of this technology to more complex surface shapes, such as ship hulls, medical devices, and water pipes. The project will also train the next generation of engineers, from K-12 students to graduate researchers, to advance light-based solutions to real-world problems. This CAREER project will employ UV-emitting glass (UEG) technology, optical waveguides that scatter ultraviolet radiation uniformly across a transparent substrate via silica nanoparticles embedded at the core-cladding interface, as an experimental platform to resolve fundamental questions about light-microorganism interactions at the biofilm attachment interface. Thrust 1 will integrate UEG substrates with custom microfluidic flow cells and high-resolution phase-contrast microscopy to quantify dose-dependent cellular kinetics across irradiance levels of 0.1-50 µW/cm², capturing attachment probability, extracellular polymeric substance (EPS) excretion timing, motility transitions, and inactivation thresholds as functions of irradiance and residence time. Parallel optical coherence tomography (OCT) imaging of UEG-integrated flow cells will provide the first in situ, real-time quantification of biofilm structural dynamics, including thickness, porosity, and roughness coefficient, under photoinduced stress, with direct comparison of internal versus external UV delivery modes across systematically varied environmental conditions (pH, temperature, salinity, flow rate, and nutrient concentration). Automated image analysis and machine learning-assisted cell tracking algorithms will extract behavioral transition kinetics and inform the development of predictive mechanistic models relating irradiance, dose, and environmental parameters to cellular and community-level outcomes. Thrust 2 will translate the light distribution principles established through UEG research to scale self-emitting UV surface technology to complex and non-planar geometries, dramatically expanding the range of surfaces and sectors that can benefit from chemical-free, light-driven biofilm prevention. Together, these research thrusts will advance fundamental photobiology and microbial photophysics while generating scalable biotechnology platforms with transformative potential for biofilm prevention in water treatment, healthcare, and marine applications This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. NSF Award ID: 2542094 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Mariana Lopes | Institution: University of Massachusetts Amherst, AMHERST, MA | Award Amount: $709,645 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2542094 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2542094.html