Papers of the Week

Hydrogen sulfide (HS) is known to participate in bacteria-induced inflammatory response in periodontal diseases. Therefore, it is necessary to quantify HS produced by oral bacteria for diagnosis and treatment of oral diseases including halitosis and periodontal disease. In this study, we introduce a paper-based colorimetric assay for detecting bacterial HS utilizing silver/Nafion/polyvinylpyrrolidone membrane and a 96-well microplate. This HS-sensing paper showed a good sensitivity (8.27 blue channel intensity/μM HS, R = 0.9996), which was higher than that of lead acetate paper (6.05 blue channel intensity/μM HS, R = 0.9959). We analyzed the difference in HS concentration released from four kinds of oral bacteria (, , , and ). Finally, the HS level in while varying the concentration of cysteine and treatment time was quantified. This paper-based colorimetric assay can be utilized as a simple and effective tool for in vitro screening of HS-producing ability of many bacteria as well as salivary HS analysis.