標題: Label-Free Impedimetric Immunosensors Modulated by Protein A/Bovine Serum Albumin Layer for Ultrasensitive Detection of Salbutamol
作者: Lin, Chia-Hung
Lin, Ming-Jie
Huang, Jie-De
Chuang, Yu-Sheng
Kuo, Yu-Fen
Chen, Jung-Chih
Wu, Ching-Chou
分子醫學與生物工程研究所
Institute of Molecular Medicine and Bioengineering
關鍵字: protein A;surface density;oriented immobilization;electrochemical impedance spectroscopy;immunosensor
公開日期: 1-二月-2020
摘要: The sensing properties of immunosensors are determined not only by the amount of immobilized antibodies but also by the number of effective antigen-binding sites of the immobilized antibody. Protein A (PA) exhibits a high degree of affinity with the Fc part of IgG antibody to feasibly produce oriented antibody immobilization. This work proposes a simple method to control the PA surface density on gold nanostructure (AuNS)-deposited screen-printed carbon electrodes (SPCEs) by mixing concentration-varied PA and bovine serum albumin (BSA), and to explore the effect of PA density on the affinity attachment of anti-salbutamol (SAL) antibodies by electrochemical impedance spectroscopy. A concentration of 100 mu g/mL PA and 100 mu g/mL BSA can obtain a saturated coverage on the 3-mercaptoproponic acid (MPA)/AuNS/SPCEs and exhibit a 50% PA density to adsorb the amount of anti-SAL, more than other concentration-varied PA/BSA-modified electrodes. Compared with the randomly immobilized anti-SAL/MPA/AuNS/SPCEs and the anti-SAL/PA(100 mu g/mL):BSA(0 mu g/mL)/MPA/AuNS/SPCE, the anti-SAL/PA(100 mu g/mL): BSA(100 mu g/mL)/MPA/AuNS/SPCE-based immunosensors have better sensing properties for SAL detection, with an extremely low detection limit of 0.2 fg/mL and high reproducibility (<2.5% relative standard deviation). The mixture of PA(100 mu g/mL):BSA(100 mu g/mL) for the modification of AuNS/SPCEs has great promise for forming an optimal protein layer for the oriented adsorption of IgG antibodies to construct ultrasensitive SAL immunosensors.
URI: http://dx.doi.org/10.3390/s20030771
http://hdl.handle.net/11536/154233
DOI: 10.3390/s20030771
期刊: SENSORS
Volume: 20
Issue: 3
起始頁: 0
結束頁: 0
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