Highly Sensitive Room-Temperature Detection of Ammonia in the Breath of Kidney Disease Patients Using Fe 2 Mo 3 O 8 /MoO 2 @MoS 2 Nanocomposite Gas Sensor.

A novel Fe ₂ Mo ₃ O ₈ /MoO ₂ @MoS ₂ nanocomposite is synthesized for extremely sensitive detection of NH ₃ in the breath of kidney disease patients at room temperature. Compared to MoS ₂ , α-Fe ₂ O ₃ /MoS ₂ , and MoO ₂ @MoS ₂ , it shows the optimal gas-sensing performance by optimizing the formation of Fe ₂ Mo ₃ O ₈ at 900 °C. The annealed Fe ₂ Mo ₃ O ₈ /MoO ₂ @MoS ₂ nanocomposite (Fe ₂ Mo ₃ O ₈ /MoO ₂ @MoS ₂ -900 °C) sensor demonstrates a remarkably high selectivity of NH ₃ with a response of 875% to 30 ppm NH ₃ and an ultralow detection limit of 3.7 ppb. This sensor demonstrates excellent linearity, repeatability, and long-term stability. Furthermore, it effectively differentiates between patients at varying stages of kidney disease through quantitative NH ₃ measurements. The sensing mechanism is elucidated through the analysis of alterations in X-ray photoelectron spectroscopy (XPS) signals, which is supported by density functional theory (DFT) calculations illustrating the NH ₃ adsorption and oxidation pathways and their effects on charge transfer, resulting in the conductivity change as the sensing signal. The excellent performance is mainly attributed to the heterojunction among MoS ₂ , MoO ₂ , and Fe ₂ Mo ₃ O ₈ and the exceptional adsorption and catalytic activity of Fe ₂ Mo ₃ O ₈ /MoO ₂ @MoS ₂ -900 °C for NH ₃ . This research presents a promising new material optimized for detecting NH ₃ in exhaled breath and a new strategy for the early diagnosis and management of kidney disease.
(© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)