A fast and sensitive colorimetric paper sensor has been developed using silver nanoprisms (Ag NPRs) with an edge length of ~50 nm for the detection of free H2S gas. We prepared two types of Ag NPRs-coated H2S sensing papers: a multi-zone patterned paper for passive (diffusion mode), and a single-zone patterned paper for pumped mode of H2S gas. The change in color intensity was quantitatively analyzed of Ag NPRs-coated paper after KCl treatment depending on the concentration of H2S gas, from yellow to purplish brown. As a result, Ag NPRs-coated H2S sensing paper showed good sensitivity with a linear range of 1.03 to 32.9 μM H2S, high selectivity, and good reproducibility and stability, together with a fast response time of 1 min. The developed H2S sensing paper was applied to detect the free H2S gas released from three types of garlic including crushed, peeled, and fresh garlic. Therefore, it can be utilized as a simple, fast, and reliable tool for on-site colorimetric detection of free H2S gas for quality control of dietary supplements and exhaled breath analysis.Graphical abstract.
Keywords: Colorimetric detection; Etching-resistance; Hydrogen sulfide gas; Sensing paper; Silver nanoprisms.