Implementing a Portable Biofilm Fluorescence Monitoring System for Enhanced Bioaerosol Source Control

JAE HEE JUNG, In Ho Kim, Jae Hak Shin, Sejong University

     Abstract Number: 727
     Working Group: Bioaerosols

Abstract
Biofilms, microscopic entities commonly found on surfaces, serve as potential reservoirs for airborne microorganisms and contribute to a number of problems, including disease outbreaks and degradation of structures and devices. This research was structured around the optical characterization of Staphylococcus epidermidis bacterial biofilm growth with the goal of building an effective optical monitoring system, which is designed to enhance biofilm management and thus significantly improve indoor air quality by reducing bioaerosols generated from biofilms. The optical properties of the biofilm were evaluated using a variety of approaches. First, a metric for the density of microorganisms in the biofilm was established, calculated by measuring the colony concentration per unit area under different growth time conditions. In parallel, a microscopic evaluation was performed to describe the structural formation of biofilms cultured under similar conditions. Ultraviolet-visible and fluorescence spectroscopy were applied to measure various optical properties, particularly absorption and fluorescence spectra. In a subsequent step, the system optics were designed according to the optimal optical measurement conditions identified for biofilm monitoring. A signal processing technique was developed to reduce interference from ambient light. This technique significantly increased the sensitivity of the system, enabling it to measure the fluorescence of weak biofilms under different indoor lighting conditions. A comparative analysis was performed to assess the bioaerosol concentration in proximity to the biofilm with and without the system, with a focus on characterizing bioaerosol management in both scenarios. Overall, this study highlights the potential for introducing an effective bioaerosol source management system, providing a scientific basis for advances in the field of bioaerosol management.

This work was supported in part by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (2022R1A2B5B02001231).