Chemiresistive gas sensors based on metal oxides have been widely applied in industrial monitoring, medical diagnosis, environmental pollutant detection, and food safety. To further enhance the gas sensing performance, researchers have worked to modify the structure and function of the material so that it can adapt to different gas types and environmental conditions. Among the numerous gas-sensitive materials, n-type TiO₂ semiconductors are a focus of attention for their high stability, excellent biosafety, controllable carrier concentration, and low manufacturing cost. This Perspective first introduces the sensing mechanism of TiO₂ nanostructures and composite TiO₂-based nanomaterials and then analyzes the relationship between their gas-sensitive properties and their structure and composition, focusing also on technical issues such as doping, heterojunctions, and functional applications. The applications and challenges of TiO₂-based nanostructured gas sensors in food safety, medical diagnosis, environmental detection, and other fields are also summarized in detail. Finally, in the context of their practical application challenges, future development technologies and new sensing concepts are explored, providing new ideas and directions for the development of multifunctional intelligent gas sensors in various application fields.

中文翻译：

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二氧化钛纳米结构在气体传感中的挑战和机遇

基于金属氧化物的化学电阻式气体传感器已广泛应用于工业监测、医疗诊断、环境污染物检测和食品安全等领域。为了进一步增强气体传感性能，研究人员致力于修改材料的结构和功能，使其能够适应不同的气体类型和环境条件。在众多的气敏材料中，n型TiO ₂半导体以其高稳定性、优异的生物安全性、可控的载流子浓度和低廉的制造成本而受到关注。本文首先介绍了TiO ₂纳米结构和TiO ₂基复合纳米材料的传感机理，然后分析了它们的气敏特性与其结构和组成之间的关系，并重点讨论了掺杂、异质结和功能应用等技术问题。_{还详细总结了TiO 2}基纳米结构气体传感器在食品安全、医疗诊断、环境检测等领域的应用和挑战。最后，结合其实际应用挑战，探讨了未来的发展技术和新的传感概念，为多功能智能气体传感器在各个应用领域的发展提供了新的思路和方向。