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Osaki S, Saito M, Nagai H, Tamiya E. Surface Modification of Screen-Printed Carbon Electrode through Oxygen Plasma to Enhance Biosensor Sensitivity. BIOSENSORS 2024; 14:165. [PMID: 38667159 PMCID: PMC11048330 DOI: 10.3390/bios14040165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/25/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024]
Abstract
The screen-printed carbon electrode (SPCE) is a useful technology that has been widely used in the practical application of biosensors oriented to point-of-care testing (POCT) due to its characteristics of cost-effectiveness, disposability, miniaturization, wide potential window, and simple electrode design. Compared with gold or platinum electrodes, surface modification is difficult because the carbon surface is chemically or physically stable. Oxygen plasma (O2) can easily produce carboxyl groups on the carbon surface, which act as scaffolds for covalent bonds. However, the effect of O2-plasma treatment on electrode performance remains to be investigated from an electrochemical perspective, and sensor performance can be improved by clarifying the surface conditions of plasma-treated biosensors. In this research, we compared antibody modification by plasma treatment and physical adsorption, using our novel immunosensor based on gold nanoparticles (AuNPs). Consequently, the O2-plasma treatment produced carboxyl groups on the electrode surface that changed the electrochemical properties owing to electrostatic interactions. In this study, we compared the following four cases of SPCE modification: O2-plasma-treated electrode/covalent-bonded antibody (a); O2-plasma-treated electrode/physical adsorbed antibody (b); bare electrode/covalent-bonded antibody (c); and bare electrode/physical absorbed antibody (d). The limits of detection (LOD) were 0.50 ng/mL (a), 9.7 ng/mL (b), 0.54 ng/mL (c), and 1.2 ng/mL (d). The slopes of the linear response range were 0.039, 0.029, 0.014, and 0.022. The LOD of (a) was 2.4 times higher than the conventional condition (d), The slope of (a) showed higher sensitivity than other cases (b~d). This is because the plasma treatment generated many carboxyl groups and increased the number of antibody adsorption sites. In summary, the O2-plasma treatment was found to modify the electrode surface conditions and improve the amount of antibody modifications. In the future, O2-plasma treatment could be used as a simple method for modifying various molecular recognition elements on printed carbon electrodes.
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Affiliation(s)
- Shuto Osaki
- AIST-Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, Photonics Center, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan (H.N.)
| | - Masato Saito
- AIST-Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, Photonics Center, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan (H.N.)
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan
| | - Hidenori Nagai
- AIST-Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, Photonics Center, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan (H.N.)
| | - Eiichi Tamiya
- AIST-Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, Photonics Center, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan (H.N.)
- SANKEN-The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki 567-0047, Osaka, Japan
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Generation of a Highly Efficient Electrode for Ethanol Oxidation by Simply Electrodepositing Palladium on the Oxygen Plasma-Treated Carbon Fiber Paper. Catalysts 2021. [DOI: 10.3390/catal11020248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In this study, a highly efficient carbon-supported Pd catalyst for the direct ethanol fuel cell was developed by electrodepositing nanostructured Pd on oxygen plasma-treated carbon fiber paper (Pd/pCFP). The oxygen plasma treatment has been shown to effectively remove the surface organic contaminants and add oxygen species onto the CFP to facilitate the deposition of nano-structured Pd on the surface of carbon fibers. Under the optimized and controllable electrodeposition method, nanostructured Pd of ~10 nm can be easily and evenly deposited onto the CFP. The prepared Pd/pCFP electrode exhibited an extraordinarily high electrocatalytic activity towards ethanol oxidation, with a current density of 222.8 mA mg−1 Pd. Interestingly, the electrode also exhibited a high tolerance to poisoning species and long-term stability, with a high ratio of the forward anodic peak current density to the backward anodic peak current density. These results suggest that the Pd/pCFP catalyst may be a promising anodic material for the development of highly efficient direct alcohol fuel cells.
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