Rapid gas sensing with high sensitivity and selectivity is pivotal in advanced production, in smart living, and increasingly in medical health applications. This study presents a novel Pt@InNiO_x nanoflake isoprene sensor that achieves an exceptionally low limit of detection (LOD) at 2 ppb, the lowest reported for isoprene sensors to date. Notably, it exhibits high selectivity and remarkable antihumidity capacity, thus meeting the stringent requirements for lung cancer screening. To unravel the sensing mechanism, we fabricate an operando DRIFTS-Raman cell coupled to online electrical measurements. It reveals that the ultrasensitive performance of Pt@InNiO_x nanoflakes stems from the activated conjugated structure of isoprene by Pt nanoclusters and from the enhanced isoprene adsorption and electron interaction due to the nanoflake morphology. The p-n junction constructed by doping Ni maintains Fermi level equilibrium, shielding it from humidity interference. Practically, we integrate these ultrasensitive Pt@InNiO_x nanoflakes into a miniaturized portable electronic device that successfully distinguishes lung cancer patients with expiratory isoprene below 40 ppb, from the healthy population with isoprene above 60 ppb, enabling an accurate diagnosis in clinics. Our work not only provides a breakthrough in low-cost, noninvasive cancer screening through breath analysis but also advances the rational design of cutting-edge gas sensing materials.

中文翻译：

---

基于In2O3的超灵敏纳米薄片用于肺癌诊断和原位光谱研究的传感机制


具有高灵敏度和选择性的快速气体传感在先进生产、智能生活以及日益增长的医疗健康应用中发挥着关键作用。本研究提出了一种新型 Pt@InNiO_x 纳米片状异戊二烯传感器，该传感器在 2 ppb 时实现了极低的检测限 （LOD），这是迄今为止报道的异戊二烯传感器的最低值。值得注意的是，它表现出高选择性和卓越的防潮能力，从而满足肺癌筛查的严格要求。为了揭示传感机制，我们制造了一个与在线电学测量耦合的原位 DRIFTS-Raman 单元。它揭示了 Pt@InNiO_x 纳米薄片的超灵敏性能源于 Pt 纳米团簇激活的异戊二烯共轭结构以及纳米薄片形态引起的增强的异戊二烯吸附和电子相互作用。通过掺杂 Ni 构建的 p-n 结保持费米能级平衡，使其免受湿度干扰。实际上，我们将这些超灵敏的 Pt@InNiO_x 纳米薄片集成到一个小型化便携式电子设备中，成功地区分了呼气异戊二烯低于 40 ppb 的肺癌患者和异戊二烯高于 60 ppb 的健康人群，从而在临床上实现准确诊断。我们的工作不仅通过呼吸分析为低成本、无创癌症筛查提供了突破，而且还推动了尖端气体传感材料的合理设计。