Well-ordered bioreceptors on atomically flat Au surfaces can be a high-performance biosensor. Cardiac troponin I proteins (cTnIs) have been regarded as a specific biomarker for acute myocardial infarction (AMI). Here, we report the accurate detection of cTnIs using an aptamer-immobilized Au nanoplate platform. The single-crystalline and atomically flat Au nanoplate was characterized by atomic force microscopy. For the precise detection of cTnI, we immobilized an aptamer that can strongly bind to cTnI onto an atomically flat Au nanoplate. Using the aptamer-immobilized Au nanoplate, cTnIs were successfully detected at a concentration of 100 aM (2.4 fg/mL) in buffer solution. Furthermore, cTnIs in serum could be identified at a concentration of 100 fM (2.4 pg/mL). The total assay time was ~7 h. Importantly, the aptamer-immobilized Au nanoplate enabled us to diagnose AMI patients accurately, suggesting the potential of the present method in the diagnosis of AMI.
Funding: This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (MSIT) (NRF-2019R1C1C1006867), the Center for BioNano Health-Guard funded by the MSIT of Korea as Global Frontier Project (H-GUARD_2013M3A6B2078950), the Bio & Medical Technology Development Program of the NRF funded by MSIT of Korea (NRF-2018M3A9E2022821), and KRIBB Research initiative Program.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (MSIT) (NRF-2019R1C1C1006867), the Center for BioNano Health-Guard funded by the MSIT of Korea as Global Frontier Project (H-GUARD_2013M3A6B2078950), the Bio & Medical Technology Development Program of the NRF funded by MSIT of Korea (NRF-2018M3A9E2022821), and KRIBB Research initiative Program.
