纳米多孔金增敏的分子印迹传感器用于气体检测的研究

This application is about to develop a QCM sensor system for detection of volatile organic compounds (VOC). The sensor will be firstly covered with nanoporous gold (NPG) leaf and further modified with molecularly imprinted polymeric (MIP) film. Techniques for immobilization of NPG on QCM surface, as well as modification of the NPG/QCM sensor with MIP will be studied and the method of determining VOCs existing in the breath of lung cancer patients as biomarkers will be developed. Our previous work has established the original two-step sensor coating technique and the modified sensor systmem has been applied as gas detector. In this research, sensitivity and specificity of the gas sensor are the most important factors that we attempted to improve. In order to fulfill this purpose, QCM sensor and its array system will be employed; furthermore, the involvement of NPG and MIP is expected to enhance the amplification of sensor signals multiply, therefore reducing the limit of detection and raiseing the specificity. Our work will not only open the way of combining NPG with QCM firstly, but also provide new experience concerning introduction of MIP and nanomaterials in sensing field. Since it has been proved that there exist specific "biomarkers" in lung cancer patients' breath, the ultimate aim of this work is to "smell" cancer in a simple and quick manner. This research is likely to render a new inexpensive strategy for quickly diagnosing the related cancer in wide scale, which is very meaningful for the early discovery and prevention of the disease.

本申请将利用纳米多孔金（NPG）和分子印迹聚合物（MIP）膜来修饰石英晶体微天平（QCM），并将其用于挥发性有机化合物的检测。研究将建立NPG在QCM上固定和MIP膜进一步修饰电极的技术，并建立所修饰传感器对目标气体肺癌标识物的特异性识别和检测的方法。前期工作已开创了通用性的传感器两步修饰技术，并完成了部分有机气体的检测，本申请的重点则放在提高传感器的灵敏性和特异性上。QCM及其阵列的应用，以及NPG和MIP的引入将实现传感器信号多重放大目的，从而降低检测限，提高专属性。本研究不仅开展了NPG用于QCM修饰的前瞻性工作，也为分子印迹技术和纳米多孔材料在传感领域的应用提供新的研究经验。课题目标是将QCM转化成用于肺癌辅助诊断的呼吸气体检测传感器。从肺癌尽早确诊可以很大程度提高病患存活率的意义出发，该产品为肺癌的大规模排查提供了全新的低成本手段，对病症的及早发现和预防有着重要意义。

肺癌是目前世界上最为常见的恶性肿瘤之一，具有发病率高而存活率低的特点，早期诊断可以极大提高肺癌的五年生存率，对于肺癌防治具有重要意义。本课题致力于研制一种方便、快捷、无损的电子检测系统和方法，能够对肺癌病人呼出的特征性气体产生响应，用于肺癌的辅助诊断。采用石英晶体微天平（QCM）作为换能元件，将纳米多孔金（NPG）和分子印迹聚合物（MIP）膜分别修饰到QCM上，继而将其用于挥发性有机化合物的检测。本研究对于NPG在QCM上固定和MIP膜进一步修饰电极的技术进行了深入研究和优化，对所修饰传感器在目标气体肺癌标识物的特异性识别和检测方面也进行了全面考察。研究发现，QCM及其阵列的应用，以及NPG和MIP的引入实现了传感器信号多重放大目的，降低了检测限，提高了专属性，即传感性能中的重要指标-灵敏性和特异性都有了较大程度的提升。本研究不仅开展了NPG用于QCM修饰的前瞻性工作，也为分子印迹技术和纳米多孔材料在传感领域的应用提供了新的研究经验。通过表面修饰化学，分子印迹自组装聚合等技术对修饰材料的涂覆过程进行改造和优化，获得的复合膜修饰的QCM传感器在用于目标气体检测中，其方法验证学实验的各项指标合格，且检测速度快，重复性好，灵敏性高，专属性好。本研究为肺癌的大规模排查提供了辅助的低成本便捷手段，对病症的及早发现和预防有着重要意义。