Measurement of low concentration and nano-quantity hydrogen sulfide in aqueous solution: measurement mechanisms and limitations

Abstract

To measure hydrogen sulfide (H2S) level in biological samples in vivo on a real-time basis with high resolution is greatly needed for advancing our understanding of the biological role of H2S. Traditional H2S measurements usually need large tissue samples and complex procedures. However, H2S concentration is very low in human bodies and the tissue sample is limited for medical treatment purposes. There is a need to develop a new paradigm for the real-time measurement of a trace amount of hydrogen sulfide with a small amount of tissue samples or in vivo. We previously reported a method to measure low concentration H2S solution using carbon nanotubes and the fluorescence spectra of Raman and confocal laser scanning microscopes. We obtained that the measurement resolution with a confocal laser scanning microscope is higher than that with a Raman microscope; in particular, 10 µM concentration difference can be detected with a confocal laser scanning microscope. In this paper, we present the underlying mechanism and limitation of this method together with other traditional methods based on the theoretical analysis, which leads to the finding of further research on the measurement of low concentration and nano-quantity H2S solution.