This paper reports an aptamer-based nanopore thin film sensor for detecting theophylline in the buffer solution and complex fluids including plant extracts and serum samples. Compared to antibody-based detection, aptamer-based detection offers many advantages such as low cost and high stability at elevated temperatures. Experiments found that this type of sensor can readily detect theophylline at a concentration as low as 0.05 µM, which is much lower than the detection limit of current lab-based equipment such as liquid chromatography (LC). Experiments also found that the aptamer-based sensor has good specificity, selectivity, and reasonable reusability with a significantly improved dynamic detection range. By using the same nanopore thin film sensors as the reference sensors to further mitigate the non-specific binding effect, the theophylline in plant extracts and serum has been detected. Only a small amount (~1 μL) of plant extracts or serum samples is required to measure theophylline. Its low cost and ease-of-operation make this type of sensor suitable for point-of-care application to monitor the theophylline level of patients in real time.

本文报道了一种基于适体的纳米孔薄膜传感器，用于检测缓冲液和复杂液体（包括植物提取物和血清样品）中的茶碱。与基于抗体的检测相比，基于适体的检测具有许多优势，例如低成本和在高温下的高稳定性。实验发现，这种类型的传感器可以很容易地检测到茶碱的浓度低至0.05 µM，这远低于当前基于实验室的设备（如液相色谱（LC））的检测极限。实验还发现，基于适体的传感器具有良好的特异性，选择性和合理的可重用性，并且动态检测范围得到显着改善。通过使用与参考传感器相同的纳米孔薄膜传感器，以进一步减轻非特异性结合效应，已检测到植物提取物和血清中的茶碱。只需少量（〜1μL）的植物提取物或血清样品即可测定茶碱。它的低成本和易操作性使这种类型的传感器适用于即时医疗应用，以实时监测患者的茶碱水平。