Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
ACS Appl Mater Interfaces. 2014 Jun 25;6(12):9061-70. doi: 10.1021/am501394r. Epub 2014 Jun 3.
Diagnostic sensing device using exhaled breath of human have critical advantages due to the noninvasive diagnosis and high potential for portable device with simple analysis process. Here, we report ultrafast as well as highly sensitive bumpy WO3 hemitube nanostructure assisted by O2 plasma surface modification with functionalization of graphene-based material for the detection of acetone (CH3COCH3) and hydrogen sulfide (H2S) which are biomarkers for the diagnosis of diabetes and halitosis, respectively. 0.1 wt % graphene oxide (GO)- and 0.1 wt % thin layered graphite (GR)- WO3 hemitube composites showed response times of 11.5 ± 2.5 s and 13.5 ± 3.4 s to 1 ppm acetone as well as 12.5 ± 1.9 s and 10.0 ± 1.6 s to 1 ppm of H2S, respectively. In addition, low limits of detection (LOD) of 100 ppb (Rair/Rgas = 1.7 for acetone and Rair/Rgas = 3.3 for H2S at 300 °C) were achieved. The superior sensing properties were ascribed to the electronic sensitization of graphene based materials by modulating space charged layers at the interfaces between n-type WO3 hemitubes and p-type graphene based materials, as identified by Kelvin Probe Force Microscopy (KPFM). Rapid response and superior sensitivity of the proposed sensing materials following cyclic thermal aging demonstrates good potential for real-time exhaled breath diagnosis of diseases.
基于呼出气体的诊断传感设备具有非侵入式诊断和适用于便携设备的巨大潜力，且分析过程简单，因此具有关键优势。在此，我们报告了一种超快且高灵敏度的凹凸 WO3 半管纳米结构，该结构通过 O2 等离子体表面改性得到增强，并功能化了基于石墨烯的材料，可用于检测丙酮（CH3COCH3）和硫化氢（H2S），这两种物质分别是诊断糖尿病和口臭的生物标志物。0.1wt%氧化石墨烯（GO）和 0.1wt%薄层石墨（GR）-WO3 半管复合材料对 1ppm 丙酮的响应时间分别为 11.5±2.5s 和 13.5±3.4s，对 1ppm H2S 的响应时间分别为 12.5±1.9s 和 10.0±1.6s。此外，检测限（LOD）低至 100ppb（在 300°C 时，Rair/Rgas=1.7 用于丙酮，Rair/Rgas=3.3 用于 H2S）。优异的传感性能归因于基于石墨烯的材料通过调制 n 型 WO3 半管和 p 型基于石墨烯的材料之间界面的空间电荷层，从而实现电子敏化，这一点通过 Kelvin 探针力显微镜（KPFM）得以证实。所提出的传感材料在循环热老化后具有快速响应和优异的灵敏度，这表明其在疾病实时呼气诊断方面具有良好的应用潜力。
