Comparison of the Fluorescence Properties of Biological Solutions and Aerosols

The identification of biological aerosols is a subject of worldwide interest because of the potential for biological terrorism and the increase in public health emergencies. Laser-induced fluorescence is widely used to investigate the fluorescence properties of biomolecules and spores in solution; however, data on the fluorescence properties of the aerosolized forms are lacking. In this study, we report the fluorescence properties of tryptophan, serotonin, tyrosine, vitamin B6, and Bacillus thuringiensis and Bacillus subtilis spores in solution and aerosol form. Our results show that the shapes of the fluorescence spectra were generally consistent between the solution and aerosol states despite some wavelength shifts in the emission spectra. In contrast, the fluorescence intensity of the emissions varied significantly between the solutions and aerosols. Given the growing global interest in accurate measurement of airborne biological molecules and particles, our findings provide a useful baseline for further research into the development of laser-induced fluorescence-based bioaerosol detection instruments and can guide the ongoing design of effective measurement and engineering technologies.