An Innovative Nanobody-Based High-Biocompatibility Gold Interdigitated Microelectrode Electrochemical Bioimpedance Sensor for the Ultrasensitive Detection of Difenacoum in Human Serum.

Liuchuan Guo,Zhiwei He,Haiyang Jiang,Sihan Wang,Yuebin Ke,Zhanhui Wang,Xiaoli Zhu,Jing Zhang

doi:10.3390/ma14143930

Abstract

Difenacoum (DIF) is one of the most widely used anticoagulant rodenticides. However, accidental or intentional ingestion of DIF seriously threatens humans and other non-target species. Therefore, a rapid and sensitive detection method to quantify DIF is urgently needed. In this study, one anti-DIF nanobody (Nb) was assembled on the surface of a gold interdigitated microelectrode (IDME) using an Au–S bond to fabricate a bioimpedance sensor. To improve the immobilization amount of Nbs on the electrode, a polycrystalline gold IDME was prepared to provide a larger surface and better biocompatibility. Thus, a novel and ultrasensitive bioimpedance sensor based on electrochemical impedance spectroscopy (EIS) was designed for the determination of DIF, and it displayed good reproducibility and stability in human serum. The proposed bioimpedance sensor displayed a wide working range, between 0.1–1000 pg/mL, with a limit of detection (LOD) of 0.1 pg/mL of DIF. This method exhibited excellent performance, good sensitivity, and reproducibility and achieved the highest sensitivity of all currently existing methods used to quantify DIF. The highly sensitive DIF detection of this proposed bioimpedance sensor indicates its potential as an efficacious approach for DIF monitoring in human serum with high accuracy and precision.

Highlights

DIF (3-(3-biphenyl-4-yl-1,2,3,4-tetrahydro-l-naphthyl)-4-hydroxycoumarin), a derivative of 4-hydroxycoumarin, is a second-generation anticoagulant rodenticide that has been used for decades worldwide as a form of rodent control [1,2]
The change in the Ret values could be used to quantify the concentration of the DIF accurately. These results demonstrated the effective assembly of the bioimpedance sensor and its ability to recognize the analyte
The developed bioimpedance sensor constructed in this study provided a high sensitivity limit of detection (LOD) of 0.1 pg/mL and wide linear range for DIF quantification, which is a better performance than that of other methods

Summary

Introduction

DIF (3-(3-biphenyl-4-yl-1,2,3,4-tetrahydro-l-naphthyl)-4-hydroxycoumarin), a derivative of 4-hydroxycoumarin, is a second-generation anticoagulant rodenticide that has been used for decades worldwide as a form of rodent control [1,2]. In 1975, DIF was developed amidst increasing concern about warfarin-resistant rats [3]. The anticoagulant activity of DIF is more effective and toxic than the first-generation anticoagulant rodenticides, such as warfarin, because of the introduction of substituted tetralinyl on the side chain [4,5]. DIF can act as an anti-vitamin K anticoagulant to block the vitamin K cycle, which stops the activity of the vitamin K-dependent clotting factor and impairs the biosynthesis of a variety of coagulation functions [6]. The use of DIF has reached its highest proportion (28.3%)

Methods

Results

Conclusion