Optimization of Electronic Impedance Spectroscopy Chips for Accurate Detection of Disease Biomarkers

陳楷文 Kai-Wen Chen1, Erick Wang2, Wen-Liang Chen1,2

1Institute of Molecular Medicine and Bioengineering, National Yang

Ming Chiao Tung University, 300093 Hsinchu, Taiwan

2Department of Biological Science & Technology, National Yang Ming

Chiao Tung University, 300093 Hsinchu, Taiwan 

Electronic impedance spectroscopy (EIS) chips are a widely-used tool for the detection of disease biomarkers. In this study, we aimed to optimize the modification conditions of EIS chips for biomarker detection. To achieve this, we measured the impedance value of the chips to ensure that the baseline was consistent, which is critical for accurate biomarker detection. Following the confirmation of consistent baseline impedance values, we applied the optimized EIS chips to detect three different biomarkers: Sars-Cov-2 spike protein receptor binding domain (RBD), human cardiac troponin I (CtnI), and canine cartilage oligomeric matrix protein (COMP). Our results revealed that the detection signals of EIS chips varied among the different biomarkers even when the same modification and detection methods were used. Therefore, it is essential to optimize the modification and detection conditions for each specific biomarker to achieve accurate results. The variations in the protein characteristics of each antibody, antigen, and their interactions with the chemicals and salts present in the detection buffer could explain the inconsistent detection signals observed. Our study provides an optimized method for modifying EIS chips that yields high baseline consistency, which is critical for biomarker detection. Furthermore, we demonstrated that the detection conditions need to be adjusted to suit the specific biomarker being tested to achieve accurate and reliable results. These findings have important implications for the development of reliable and efficient biomarker detection strategies in the future.