Isoprene is a typical biomarker for nonalcoholic fatty liver disease (NAFLD) and can be used for early screening in breath diagnosis. In this study, a simple hydrothermal synthesis of flower-like Cr₂O₃-doped In₂O₃ nanorods clusters materials for ultra-low isoprene detection was reported. This special flower-like nanorods clusters structure has the large specific surface area and the Cr₂O₃ doping improves in the distribution of different oxygen components, crystallite size, and carrier concentration, which synthetically contributes to the enhanced isoprene sensing performance. The results show that among all the sensors, the 1 wt% Cr₂O₃-doped In₂O₃ sensor exhibits reliable ppb-level detection ability with a concentration less than 5 ppb. Meanwhile, the sensor shows good long-term stability for 4 weeks and considerable selectivity over other common breathing gases (benzene, acetone, octane, pentane, ethanol, ammonia, and nitrogen dioxide). Furthermore, the sensor has good humidity resistance under different ambient humidity (0–92% RH). Thus, we believe the sensor based on the flower-like Cr₂O₃-doped In₂O₃ nanorods clusters has a potential application value for the detection of trace isoprene in breath analysis.

异戊二烯是非酒精性脂肪肝疾病（NAFLD）的典型生物标志物，可用于呼吸道诊断的早期筛查。在这项研究中，报告了一种简单的水热法合成的花状Cr ₂ O ₃掺杂In ₂ O ₃纳米棒簇材料，用于超低异戊二烯检测。这种特殊的花状纳米棒簇结构具有较大的比表面积，并且Cr ₂ O ₃掺杂改善了不同氧组分的分布，微晶尺寸和载流子浓度，从而综合促进了异戊二烯感测性能的提高。结果表明，在所有传感器中，1 wt％Cr ₂ O ₃掺杂的In ₂ O ₃传感器具有可靠的ppb级检测能力，且浓度低于5 ppb。同时，该传感器在4周内显示出良好的长期稳定性，并且与其他常见的呼吸气体（苯，丙酮，辛烷，戊烷，乙醇，氨和二氧化氮）相比具有相当高的选择性。此外，该传感器在不同的环境湿度（0–92％RH）下具有良好的抗湿性。因此，我们认为基于花状Cr ₂ O ₃掺杂的In ₂ O ₃纳米棒簇的传感器对于呼吸分析中痕量异戊二烯的检测具有潜在的应用价值。