Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
Lab Chip. 2012 Mar 7;12(5):901-5. doi: 10.1039/c2lc20922e. Epub 2012 Jan 16.
We developed and characterized a rapid, sensitive and integrated optical vapor sensor array for micro-gas chromatography (μGC) applications. The sensor is based on the Fabry-Pérot (FP) interferometer formed by a micrometre-thin vapor-sensitive polymer layer coated on a silicon wafer. The thickness and the refractive index of the polymer vary in response to the vapor analyte, resulting in a change in the reflected intensity of the laser impinged on the sensor. In our study, four different polymers were coated on four wells pre-etched on a silicon wafer to form a spatially separated sensor array. A CMOS imager was employed to simultaneously monitor the polymers' response, thus enabling multiplexed detection of a vapor analyte passing through the GC column. A sub-second detection time was demonstrated. In addition, a sub-picogram detection limit was achieved, representing orders of magnitude improvement over the on-chip vapor sensors previously reported.
我们开发并表征了一种用于微气相色谱 (μGC) 应用的快速、灵敏且集成的光学蒸汽传感器阵列。该传感器基于法布里-珀罗 (FP) 干涉仪，由涂覆在硅片上的微米厚的蒸汽敏感聚合物层形成。聚合物的厚度和折射率会响应蒸气分析物而变化，从而导致激光撞击传感器时的反射强度发生变化。在我们的研究中，将四种不同的聚合物涂覆在硅片上预先蚀刻的四个井中，形成空间上分离的传感器阵列。采用 CMOS 成像仪同时监测聚合物的响应，从而能够对通过 GC 柱的蒸气分析物进行多路检测。已证明检测时间可短至亚秒。此外，还实现了皮克以下的检测极限，相对于先前报道的片上蒸气传感器，这是数量级的提高。
