Yan Kai, Haque Al-Monsur Jiaul, Nandhakumar Ponnusamy, Bhatia Aman, Lee Nam-Sihk, Yoon Young Ho, Yang Haesik
Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan, 46241, Republic of Korea.
EONE Laboratories, Incheon, 22014, Republic of Korea.
Biosens Bioelectron. 2020 Oct 1;165:112337. doi: 10.1016/j.bios.2020.112337. Epub 2020 Jun 20.
In horseradish peroxidase (HRP)-based electrochemical immunosensing, an appropriate HRP substrate needs to be chosen to obtain a high electrochemical signal-to-background ratio. This is limited by the unwanted electrochemical reduction of HO, oxidation of the substrate, and the slow electrochemical reduction of the product. Herein, we report acetaminophen (AMP) as a new HRP substrate that allows for highly sensitive immunosensing. Electrochemical behavior and immunosensing performance using AMP are compared with those using the most popular HRP substrate, hydroquinone (HQ). To maintain a high electrocatalytic activity even at an electrode modified with an immunosensing layer, an indium tin oxide electrode partially modified with reduced graphene oxide is employed. AMP allows for a higher signal-to-background ratio than HQ, because the formal potential of AMP is 0.28 V higher than that of HQ and the redox reaction of AMP is as reversible as that of HQ, resulting in a lower detection limit in a sandwich-type immunoassay using AMP for thyroid-stimulating hormone detection. The calculated detection limit is ~0.2 pg/mL. The use of AMP as an HRP substrate is especially promising for highly sensitive electrochemical immunoassays.
在基于辣根过氧化物酶（HRP）的电化学免疫传感中，需要选择合适的HRP底物以获得高电化学信号背景比。这受到HO不必要的电化学还原、底物氧化以及产物缓慢的电化学还原的限制。在此，我们报道对乙酰氨基酚（AMP）作为一种新型HRP底物，可实现高灵敏度免疫传感。将使用AMP的电化学行为和免疫传感性能与使用最广泛的HRP底物对苯二酚（HQ）进行比较。为了即使在修饰有免疫传感层的电极上也能保持高电催化活性，采用了部分用还原氧化石墨烯修饰的氧化铟锡电极。与HQ相比，AMP具有更高的信号背景比，这是因为AMP的形式电位比HQ高0.28 V，且AMP的氧化还原反应与HQ一样可逆，从而在使用AMP进行促甲状腺激素检测的夹心型免疫分析中具有更低的检测限。计算得出的检测限约为0.2 pg/mL。将AMP用作HRP底物对于高灵敏度电化学免疫分析尤其具有前景。
