Rapid electrical biosensor consisting of DNA aptamer/carbon nanonetwork on microelectrode array for cardiac troponin I in human serum

Rapid detection of cardiac biomarkers is important for the early diagnosis of acute myocardial infarction (AMI). Currently, cardiac troponin I (cTnI) is the standard biomarker for precise diagnosis of AMI. It is essential for rapid diagnosis of AMI patient. Herein, we presented the rapid electrical biosensor composed of a carbon nanotube network (CNN) and DNA aptamer on a microelectrode array to detect cTnI in human serum sample. The island-shaped Au microgap electrodes array was used to provide a high signal-to-noise ratio response and maximize detection sensitivity. In addition, an alternating current electrothermal flow (ACEF) method was introduced to improve the affinity between the DNA aptamer and the target molecule, and cTnI was detected within 10 min using this method. The current change was analyzed using pulse measurement for 100 μs, and the integrated current method was proposed to improve the performance of the sensor platform. This biosensor can detect cTnI in a wide linear range from 1 pM to 100 nM in 10 % human serum. The limit of detection is 6.59 fM, indicating high selectivity. Thus, the proposed electrical biosensor platform may facilitate rapid and early detection of AMI in the future.