Chae, Myung-Sic Kim, Jinsik Jeong, Dahye Kim, Young soo Roh, Jee Hoon Lee, Sung Min Heo, Youhee Kang, Ji Yoon Lee, Jeong Hoon Yoon, Dae Sung Kim, Tae Geun Chang, Suk Tai Hwang, Kyo Seon 2024-01-20T01:30:53Z 2024-01-20T01:30:53Z 2021-09-05 2017-06 0956-5663 https://pubs.kist.re.kr/handle/201004/122671 We performed oxygen plasma treatment on reduced graphene oxide (rGO) to improve its surface reactivity with respect to biomolecular interactions. Oxygen-plasma-treated rGO surfaces were employed as reactive interfaces for the detection of amyloid-beta (A beta) peptides, the pathological hallmarks of Alzheimer&apos;s disease (AD), as the target analytes. By measuring the changes in electrical characteristics and confirmation through topographic analysis, the oxygen-plasma-treated rGO sensors had enhanced surface functionality for better antibody immobilization and sensing performance, with a 3.33-fold steeper slope for the electrical responses versus analyte concentration curve (logarithmic scale) compared to the untreated. The elicited biomolecular reactivity of the rGO surfaces with the oxygen plasma treatment remained at 46-51% of the initial value even after aging for 6 h in ambient conditions. This phenomenon was also confirmed by pretreating the rGO surfaces with a blocking agent and subsequently subjecting them to antibody immobilization. Finally, the feasibility of the oxygen-plasma-treated rGO sensors as a diagnostic tool was evaluated with clinical samples of neural-derived exosomal A beta peptides extracted from apparent AD patients and normal controls (NC). In contrast to the untreated sensors (p=0.0460), the oxygen-plasma-treated rGO sensors showed a significant p-value in the identification of clinical samples of AD and NC subjects (p < 0.001). These results suggest that oxygen plasma treatment improves sensor performance without complicated fabrication procedures and should aid in the development of novel diagnostic tools based on carbon nanomaterials. English Pergamon Press Ltd. Enhancing surface functionality of reduced graphene oxide biosensors by oxygen plasma treatment for Alzheimer&apos;s disease diagnosis Article 10.1016/j.bios.2016.10.049 1 Biosensors and Bioelectronics, v.92, pp.610 - 617 Biosensors and Bioelectronics 92 610 617 N scie scopus 000396946600084 2-s2.0-85008177115 Biophysics Biotechnology & Applied Microbiology Chemistry, Analytical Electrochemistry Nanoscience & Nanotechnology Biophysics Biotechnology & Applied Microbiology Chemistry Electrochemistry Science & Technology - Other Topics Article CARBON NANOTUBES DEPOSITION DISCHARGE PROTEINS RNAS Reduced graphene oxide Oxygen plasma treatment Biosensor Alzheimer&apos s diseases Exosome