As the most widely used gas sensors, metal oxide semiconductor (MOS)-based chemiresistors have been facing great challenges in achieving ppb-level and selective detection of the target gas. The rational design and employment of bimetallic nanocatalysts (NCs) are expected to address this issue. In this work, the well-shaped and monodispersed AuPt NCs (diameter ≈ 9 nm) were functionalized on one-dimensional (1D) In₂O₃ nanofibers (NFs) to construct efficient gas sensors. The sensor demonstrated dual-selective and ppb-level detection for ozone (O₃) and acetone (C₃H₆O) at different optimal working temperatures. For the possible application exploitation, a circuit was designed to monitor O₃ concentration and provide warnings when the concentration safety limit (50 ppb) was exceeded. Moreover, simulated exhaled breath measurements were also carried out to diagnose diabetes through C₃H₆O concentration. The selective detection for O₃ and C₃H₆O was further analyzed by principal component analysis (PCA). The drastically enhanced sensing performances were attributed to the synergistic catalytic effect of AuPt NCs. Both the “spillover effect” and the Schottky barrier at the interfaces of AuPt NCs and In₂O₃ NFs promoted the sensing processes of O₃ and C₃H₆O.

中文翻译：

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纳米级双金属 AuPt 功能化金属氧化物化学电阻器：臭氧和丙酮的 Ppb 级和选择性检测

作为应用最广泛的气体传感器，基于金属氧化物半导体（MOS）的化学电阻器在实现ppb级和选择性检测目标气体方面一直面临着巨大的挑战。双金属纳米催化剂 (NC) 的合理设计和使用有望解决这个问题。在这项工作中，形状良好且单分散的 AuPt NC（直径 ≈ 9 nm）在一维（1D）In ₂ O ₃纳米纤维（NF）上被功能化以构建高效的气体传感器。该传感器展示了在不同的最佳工作温度下对臭氧 (O ₃ ) 和丙酮 (C ₃ H ₆ O) 的双选择性和 ppb 级检测。为了可能的应用开发，设计了一个电路来监控 O ₃浓度并在超过浓度安全限值 (50 ppb) 时发出警告。此外，还进行了模拟呼气测量，以通过 C ₃ H ₆ O 浓度诊断糖尿病。通过主成分分析(PCA)进一步分析了对O ₃和C ₃ H ₆ O的选择性检测。显着增强的传感性能归因于 AuPt NC 的协同催化作用。AuPt NCs和In ₂ O _{3 NFs界面处的“溢出效应”和肖特基势垒都促进了O 3}和C ₃ H ₆ O的传感过程。