College of Sciences, Northeastern University, Shenyang 110004, China.
ACS Sens. 2023 Jul 28;8(7):2824-2833. doi: 10.1021/acssensors.3c00774. Epub 2023 Jun 22.
As a biomarker of periodontitis, sensitive and timely monitoring of hydrogen sulfide (HS) in exhaled breath at room temperature (RT) is important for the early intervention of oral diseases. However, the required high operation temperature to achieve high sensitivity is still a technical challenge for directly monitoring exhaled breath. In this study, by integrating metal-organic frameworks (MOFs) into self-aligned TiO nanotube arrays (NTs), a chemiresistor gas sensor with outstanding sensitivity and selectivity was constructed for the detection of HS at RT. The precise regulation of a Co(III)-based MOF CoBDC-NH (BDC-NH = 2-aminoterephthalic acid) not only induced more active surface for the preconcentration of the target gas but also caused a buildup of Z-scheme heterojunctions in the HS atmosphere that induced an ultrahigh sensitivity at RT via 365 nm light-emitting diode irradiation. The response and recovery times decreased to ∼50 and ∼28%, respectively, when this system was exposed to UV light. The sensing chips based on the as-prepared TiO/CoBDC-NH NTs exhibited the highest-ranking HS sensing performance, i.e., a limit of detection of 1.3 ppb and excellent selectivity even to 100 times high concentration of interference gases, owing to the synergistic chemical environment provided by NH-functionalized Co-MOFs and abundant photogenerated electrons provided by Z-scheme heterojunctions. This sensing chip was also used in a practical application for the timely monitoring of halitosis from direct exhaled breath. This study provides a reliable and sensitive design for clinically aiding the timely detection of HS in a complex oral environment.
作为牙周炎的生物标志物，室温下（RT）呼出气体中硫化氢（HS）的敏感和及时监测对于口腔疾病的早期干预很重要。然而，为了实现高灵敏度，直接监测呼出气体所需的高操作温度仍然是一个技术挑战。在这项研究中，通过将金属有机骨架（MOFs）整合到自对准的 TiO 纳米管阵列（NTs）中，构建了一种具有出色灵敏度和选择性的化学电阻式气体传感器，用于 RT 下 HS 的检测。精确调节基于 Co（III）的 MOF CoBDC-NH（BDC-NH = 2-氨基对苯二甲酸）不仅诱导了更多的活性表面来预浓缩目标气体，而且在 HS 气氛中形成了 Z 型异质结，通过 365nm 发光二极管照射在 RT 下诱导出超高灵敏度。当该系统暴露于紫外光下时，响应和恢复时间分别降至约 50%和 28%。基于制备的 TiO/CoBDC-NH NTs 的感测芯片表现出最高的 HS 感测性能，即检测限低至 1.3 ppb，即使对 100 倍高浓度的干扰气体也具有出色的选择性，这归因于 NH 功能化 Co-MOFs 提供的协同化学环境和 Z 型异质结提供的丰富光生电子。该感测芯片还用于直接呼出的口气中及时监测口臭的实际应用。这项研究为临床在复杂口腔环境中及时检测 HS 提供了可靠和敏感的设计。
