Electrochemical Sensing of Hydrogen Sulfide Traces in Biological Samples (Supporting Information)

Given that trace level H₂S quantitation in biological samples currently requires expensive and time-consuming instrumental procedures, we herein developed an electrochemical Ag/C sensor for the detection of H₂S in protein-containing neutral solutions. The detection principle was based on the increase in galvanic current that was elicited by the sulfidation of the Ag electrode and was linearly dependent on the concentration of H₂S. This linear relationship enabled the quantitation of H₂S in the concentration range of 0.037–6.7 µmol L⁻¹ in mock biological samples without any pretreatment, highlighting the potential of the Ag/C sensor for the analysis of water quality and food, blood, and other biological samples.