Electrochemical biosensor using SnO2 colloidal quantum wire for monitoring the interaction of microcystin antigen-antibody

Qing Huang; RuiQin Gu; Yunong Zhao; Huibing Fu; Huan Liu

doi:10.1016/j.bioelechem.2023.108504

Electrochemical biosensor using SnO₂ colloidal quantum wire for monitoring the interaction of microcystin antigen-antibody

Bioelectrochemistry. 2023 Dec:154:108504. doi: 10.1016/j.bioelechem.2023.108504. Epub 2023 Jul 13.

Authors

Qing Huang¹, RuiQin Gu², Yunong Zhao², Huibing Fu³, Huan Liu⁴

Affiliations

¹ School of Integrated Circuits, School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics, Optics Valley Laboratory, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; Wenzhou Advanced Manufacturing Institute, Huazhong University of Science and Technology, Wenzhou, Zhejiang 325035, China.
² School of Integrated Circuits, School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics, Optics Valley Laboratory, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
³ Zhengzhou Winsen Electronic Technology Co., LTD, Zhengzhou, Henan 450001, China.
⁴ School of Integrated Circuits, School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics, Optics Valley Laboratory, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; Wenzhou Advanced Manufacturing Institute, Huazhong University of Science and Technology, Wenzhou, Zhejiang 325035, China. Electronic address: huan@hust.edu.cn.

PMID: 37459748
DOI: 10.1016/j.bioelechem.2023.108504

Abstract

Electrochemical sensors that incorporate immunoassay principles have the ability to monitor dynamic processes of antigen-antibody interactions in real time. In this study, a gold electrode was modified with tin dioxide colloidal quantum wire (SnO₂ QWs) and then coated with the leucine/arginine subtype microcystin (MC-LR) antibody. The active site of SnO₂ QWs that was not bound by MC-LR antibody was then passivated with bovine serum protein (BSA). When the MC-LR antigen binds specifically to the antibodies on the electrode's surface, it triggers electrochemical reactions and generates electrical signals at specific voltage conditions. The SnO₂ QW exhibits excellent electron transport ability, and its ability to form a loose and porous microstructure on the gold electrode surface, which is conducive to the receptor function of the biosensor. The results show a high affinity between the MC-LR antigen and antibody, ranging from 1 pg/mL to 10 ng/mL of MC-LR antigen concentration. The kinetic characteristics of the immune reaction between MC-LR antigen and antibody were elucidated, obtaining a binding constant of 1.399 × 10¹¹ M^-1 and a dissociation constant of 7.147 pM, demonstrating the potential of electrochemical biosensing technology in biomolecular interactions.

Keywords: Binding constant; Biomolecular interactions; Dissociation constant; Electrochemical biosensor; Microcystin.

MeSH terms

Antibodies
Biosensing Techniques*
Gold / chemistry
Immunoassay / methods
Limit of Detection
Microcystins*

Substances

Microcystins
Gold
Antibodies