Rapid detection of theophylline using aptamer-based nanopore thin film sensor

This paper reports, for the first time, an aptamer-based nanopore thin film sensor for detecting theophylline in buffer and complex fluids. 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, without any optimization, can detect theophylline at a concentration as low as 0.2 μM, which is comparable to the detection limit of current lab-based equipment such as liquid chromatography (LC). Experiments also found the aptamer-based sensor has good specificity and selectivity. By using some nanopore thin film sensors as the reference sensors to further cancel out the non-specific binding effect, the theophylline in plant extract has been detected successfully.