Localized surface plasmon resonance sensing of hydrogen sulfide using zinc oxide film

A localized surface plasmon resonance (LSPR) sensor for hydrogen sulfide (H₂S) has been developed by coating a gold nanopattern with zinc oxide (ZnO) film. H₂S detection was achieved by monitoring changes in absorbance at a specific wavelength in the LSPR spectrum. The absorbance increased during exposure to H₂S and remained constant after H₂S ceased. These responses indicate that the sensor can measure the integrated concentrations of H₂S. The sensitivity to H₂S was enhanced with increasing relative humidity, enabling detection of 0.05-3 ppm H₂S within 10 min at 70% relative humidity. The sensor's sensitivity and LSPR spectrum could be restored by heating it at 500 °C in air. Notably, the sensor did not respond to methyl mercaptan or dimethyl sulfide, demonstrating high selectivity for H₂S. This study highlights the potential of the ZnO-deposited LSPR sensor for highly sensitive and selective detection of H₂S.