Related Experiment Video
Updated: Jan 28, 2026

A Sensitive Visual Method for the Detection of Hydrogen Sulfide Producing Bacteria
Published on: June 27, 2022
Screen-Printed Sensors for Colorimetric Detection of Hydrogen Sulfide in Ambient Air
Laura Engel1, Karina R Tarantik2, Carolin Pannek3
1Fraunhofer Institute for Physical Measurement Techniques IPM, 79110 Freiburg, Germany. laura.engel@ipm.fraunhofer.de.
Abstract:
A fast and sensitive method to monitor hydrogen sulfide (H₂S) in ambient air based on a visible color change of a printed disposable sensor has been developed. As gas-sensitive material, an immobilized copper(II) complex of the azo dye 1-(2-pyridylazo)-2-naphtol (H-PAN) was synthesized and prepared in an ethyl cellulose matrix for screen printing. If H₂S is present in ambient air, the gas sensitive layer changes its color from purple to yellow. A pre-primed polyethylene (PE) foil and a coated offset paper served as the printing substrate. The colorimetric response to the target gas was measured by UV/Vis spectroscopy in reflection at H₂S concentrations between 1 to 20 ppm. Possible cross-sensitivities of the printed sensors towards methane (CH₄), formaldehyde (CH₂O), carbon monoxide (CO), ammonia (NH₃), and nitrogen dioxide (NO₂), as well as the long-term stability was investigated. Furthermore, reflection measurements of the Cu-PAN complex on an amorphous silica powder under gas admission served as preliminary test for the subsequent paste development.
More Related Videos
Related Concept Videos
Hydrogen Bonds
Hydrogen Bonds Control the World!
Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are unequally shared....
Hydrogen Bonds
Preparation and Reactions of Sulfides
Structure and Nomenclature of Thiols and Sulfides
Air-entraining Agents
Reduction of Alkenes: Catalytic Hydrogenation
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...

