Bismuth-Based, Disposable Sensor for the Detection of Hydrogen Sulfide Gas

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• 作者：Samuel M. Rosolina ; Thomas S. Carpenter ; Zi-Ling Xue
• 刊名：Analytical Chemistry
• 出版年：2016
• 出版时间：February 2, 2016
• 年：2016
• 卷：88
• 期：3
• 页码：1553-1558
• 全文大小：320K
• ISSN：1520-6882

文摘

A new sensor for the detection of hydrogen sulfide (H₂S) gas has been developed to replace commercial lead(II) acetate-based test papers. The new sensor is a wet, porous, paper-like substrate coated with Bi(OH)₃ or its alkaline derivatives at pH 11. In contrast to the neurotoxic lead(II) acetate, bismuth is used due to its nontoxic properties, as Bi(III) has been a reagent in medications such as Pepto-Bismol. The reaction between H₂S gas and the current sensor produces a visible color change from white to yellow/brown, and the sensor responds to ≥30 ppb H₂S in a total volume of 1.35 L of gas, a typical volume of human breath. The alkaline, wet coating helps the trapping of acidic H₂S gas and its reaction with Bi(III) species, forming colored Bi₂S₃. The sensor is suitable for testing human bad breath and is at least 2 orders of magnitude more sensitive than a commercial H₂S test paper based on Pb(II)(acetate)₂. The small volume of 1.35-L H₂S is important, as the commercial Pb(II)(acetate)₂-based paper requires large volumes of 5 ppm H₂S gas. The new sensor reported here is inexpensive, disposable, safe, and user-friendly. A simple, laboratory setup for generating small volumes of ppb–ppm of H₂S gas is also reported.