Department of Mechanical Engineering and Materials Science, and Institute of Materials Science and Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States.
Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States.
ACS Appl Mater Interfaces. 2022 Jan 19;14(2):3207-3217. doi: 10.1021/acsami.1c22173. Epub 2022 Jan 7.
Chemiresistors based on metal-insulator-metal structures are attractive transducers for rapid tracing of a wide repertoire of (bio)chemical species in the vapor phase. However, current fabrication techniques suffer greatly from sensor-to-sensor variability, limiting their reproducible and reliable application in real-world settings. We demonstrate a novel, facile, and ubiquitously applicable strategy for fabricating highly reliable and reproducible organothiol-functionalized gold nanoisland-based chemiresistors. The novel fabrication technique involves iterative in situ seeding, growth, and surface functionalization of gold nanoislands on an interdigitated electrode, which in turn generates a multi-layered densely packed continuous gold nanoisland film. The chemiresistors fabricated using the proposed strategy exhibited high sensor-to-sensor reproducibility owing to the controlled iterative seeding and growth-based fabrication technique, long-term stability, and specificity for detection and identification of a wide variety of volatile organic compounds. Upon exposure to a specific odor, the chemiresistor ensemble comprised nine different chemical functionalities and produced a unique and discernable odor fingerprint that is reproducible for at least up to 90 days. Integrating these odor fingerprints with a simple linear classifier was found to be sufficient for discriminating between all six odors used in this study. We believe that the fabrication strategy presented here, which is agnostic to chemical functionality, enables fabrication of highly reliable and reproducible sensing elements, and thereby an adaptable electronic nose for a wide variety of real-world gas sensing applications.
基于金属-绝缘体-金属结构的化学电阻器是快速追踪气相中多种（生物）化学物质的有吸引力的传感器。然而，当前的制造技术在传感器之间存在很大的可变性，限制了它们在实际环境中的可重复和可靠应用。我们展示了一种新颖、简便且普遍适用的策略，用于制造高度可靠和可重复的有机硫醇功能化金纳米岛基化学电阻器。这种新颖的制造技术涉及在叉指电极上进行迭代原位种子、生长和表面功能化的金纳米岛，从而生成多层密集排列的连续金纳米岛膜。由于采用了受控的迭代种子和基于生长的制造技术，所制造的化学电阻器具有很高的传感器间可重复性、长期稳定性和对各种挥发性有机化合物的检测和识别的特异性。暴露于特定气味时，由九种不同化学官能团组成的化学电阻器组产生了独特且可辨别的气味指纹，至少可重复 90 天。将这些气味指纹与简单的线性分类器集成，足以区分本研究中使用的所有六种气味。我们相信，这里提出的制造策略对化学官能团是不可知的，能够制造出高度可靠和可重复的传感元件，从而为各种实际气体传感应用提供了适应性强的电子鼻。
