Detection of water system biofilms using fluorescence spectroscopy for contamination monitoring

Abstract

The problem of water contamination is a pressing one. Nearly 800 million people around the world do not have basic access to clean drinking water, which results in millions of waterborne infections annually. Current regulations and control methods are proving to be insufficient in water contamination monitoring, largely due to lack of suitable methods and long processing times.

This study explores the concept of fluorescence spectroscopy as a method of real-time water quality control. Pathogens, often existing in biofilm form, exhibit intrinsic fluorescence in the visible region. This has been confirmed by multiple studies, which also show correlation between fluorescence intensity levels and bacterial cell amounts, meaning that increasing fluorescence can indicate increase of contaminants in water. Fluorescence spectroscopy by itself lacks specificity, however when combined with other methods, it can successfully act as a preventative contamination monitoring method.

The outcome of the method analysis is confirmed by a fluorescence measurement performed on a biofilm sample taken from a water pipe in Tampere, Finland. Despite unknown pathogen concentration and biofilm composition, fluorescence is successfully observed and is speculated to result from NADH and pyridoxine, which are common intrinsic fluorophores found in microbes.