A long-term operating algal biosensor for the rapid detection of volatile toxic compounds

A method for the stable long-term immobilization of microalgal cultures was developed. Immobilized Klebsormidium cultures were used in a biosensor system for air monitoring. The measurement of biosensor response was performed using several parameters obtained from the PAM chlorophyll fluorescence technique. To test biosensor response on toxic compounds methanol and formaldehyde, classified as volatile organic compounds (VOC), were used in concentrations relevant to human health. Our results showed that quantitative detection of methanol vapour by the biosensor is possible within minutes at concentrations from 75 to 350 ppm. Additionally, due to reversibility of the biosensor response signal and long-term stability, the biosensor was operational for 30 days with repeated exposure periods to methanol vapour. We conclude that the algal biosensor, in principle, is suitable to detect volatile toxic compounds such as methanol and formaldehyde.