A novel impedimetric biosensor based on titanium nitride nano-electrode arrays for influenza A H1N1 testing

Abstract

The development of point-of-care testing devices for real-time detection of influenza A H1N1 virus is critical for early diagnosis, and for continuous disease monitoring. In this study, we developed a novel impedimetric biosensor for detecting influenza A H1N1 virus, using a nano-electrode array fabricated through standard complementary metal-oxide-semiconductor technology. Each nano-electrode is a raised structure with a radius of 100 nanometers and a height of 200 nanometers. Titanium nitride was chosen as the electrode material for its biocompatibility and compatibility with semiconductor processes. The electrode surfaces were modified by diazonium electrografting to introduce carboxyl groups, which enabled antibody immobilization via carbodiimide coupling chemistry. We analyzed the relationship between the reduction peak current and the percentage change in charge transfer resistance before and after each modification step, and further examined the correlation between changes during modification and antibody binding. The completed biosensor successfully detected influenza A H1N1 antigens in phosphate-buffered saline, achieving a detection limit of 0.00025 EU/mL. The sensor’s response also showed a strong positive correlation with viral RNA content (Pearson r = 0.9702), indicating its potential for quantitative virus detection. These results demonstrate the feasibility of using semiconductor-based nano-electrode array biosensors for point-of-care infectious disease diagnostics.