Directly measuring Fe(<scp>iii</scp>)-catalyzed SO2 oxidation rate in single optically levitated droplets

We directly measure the Fe(iii)-catalyzed SO2 conversion in single microdroplet trapped and levitated with a gradient-force aerosol optical tweezer. There was a significant acceleration in the formation of SO2 to sulfate conversion on the surface of the aerosol microdroplets.