Embedding gold nanoclusters in metal-organic frameworks as a dual-channel hydrogel optical sensor for hydrogen sulfide detection

Abstract

Simple, efficient, and real-time monitoring technologies for hydrogen sulfide (H₂S) are essential considering its significance role in environmental and physiological scenarios. However, on-site detection of H₂S is challenged by weak anti-interference capability, poor selectivity, and complex operation. Here, we introduce a dual-channel hydrogel sensor combining fluorescence and colorimetric channels, which is portable for H₂S detection. By adopting the "bottle-around-ship" strategy to incorporate gold nanoclusters (AuNCs) within metal-organic-frameworks (MOFs), the luminescence efficiency and stability of the sensor were enhanced, which can be ascribed to the spatial confinement effect. This composite material exhibits low detection limits (5.4 μM), rapid response (<30 s), robust resistance to interference, and integration capabilities with smartphones. The independent fluorescence and colorimetric channels of the hydrogel sensor enable selective H₂S responses when exposed to UV and visible light. Additionally, by combining dual-mode responses with logic devices, this hydrogel platform enables fast and precise H₂S identification. This approach presents a promising pathway for advancing portable H₂S detection technologies.