Enhancing surface functionality of reduced graphene oxide biosensors by oxygen plasma treatment for Alzheimer's disease diagnosis.
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 (Aβ) peptides, the pathological hallmarks of Alzheimer'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 6h 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 Aβ 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.
Center for BioMicrosystems, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; School of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea.
Myung-Sic
MS
Chae
Center for BioMicrosystems, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea.
Jinsik
J
Kim
Center for BioMicrosystems, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea.
Dahye
D
Jeong
Convergence Center for Dementia, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Department of Pharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 02447, Republic of Korea.
YoungSoo
Y
Kim
Department of Neurology, Asan Medical Center, Ulsan University College of Medicine, Seoul 05505, Republic of Korea.
Jee Hoon
JH
Roh
School of Chemical Engineering and Materials Science, Chung-Ang University, Seoul 06974, Republic of Korea.
Sung Min
SM
Lee
Center for BioMicrosystems, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea.
Youhee
Y
Heo
Center for BioMicrosystems, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea.
Ji Yoon
JY
Kang
Department of Electrical Engineering, Kwangwoon University, Seoul 01897, Republic of Korea.
Jeong Hoon
JH
Lee
School of Biomedical Engineering, Korea University, Seoul 02841, Republic of Korea.
Dae Sung
DS
Yoon
School of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea. Electronic address: tgkim1@korea.ac.kr.
Tae Geun
TG
Kim
School of Chemical Engineering and Materials Science, Chung-Ang University, Seoul 06974, Republic of Korea. Electronic address: stchang@cau.ac.kr.
Suk Tai
ST
Chang
Center for BioMicrosystems, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea. Electronic address: kshwang@kist.re.kr.
Kyo Seon
KS
Hwang
D000544:Alzheimer Disease / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000032:analysis*; D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D055354:Exosomes / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation; D049329:Nanostructures / Q000737:chemistry; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*; D058626:Plasma Gases / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013499:Surface Properties
D016229:Amyloid beta-Peptides; D055910:Antibodies, Immobilized; D010087:Oxides; D058626:Plasma Gases; D006108:Graphite; D010100:Oxygen
Alzheimer's diseases; Biosensor; Exosome; Oxygen plasma treatment; Reduced graphene oxide