Real-time quantitative detection of H₂S for assessing fish freshness using a gas-controlled micro-drainage device.

Hydrogen sulfide (H₂S), a potential indicator of fish freshness, necessitates the development of rapid quantitative detection methods for ensuring food safety. Nevertheless, most of the current methods for H₂S detection cannot simultaneously meet the requirements of ease-of-use and quantifiability. In this study, we introduce an innovative quantitative detection method of H₂S that employs a gas-controlled micro-drainage device with an electronic balance as readout. When H₂S, a product of fish spoilage, is present, it interacts with Platinum nanoparticles (PtNPs)-catalase nanozyme, affecting their catalytic activity and, subsequently, the weight of overflowed water. This allows for the conversion of H₂S concentration into a measurable weight change signal. The sensor demonstrates an inverse correlation between the mass of overflowed water and H₂S concentration (0-50 μM) with a detection limit of 0.43 μM. This device enables sensitive, real-time, and quantitative weighing analysis of...