Signal Amplification to Improve Electrochemical Biosensing for Infectious Diseases.

Infectious disease detection and monitoring are critical for public health management. Electrochemical biosensors have emerged as promising tools for rapid and sensitive detection of infectious diseases. This review explores signal amplification approaches to improve the sensitivity and limit of detection of electrochemical biosensors for infectious diseases. Enzymatic signal amplification methods, utilizing enzymes such as endonuclease, nucleotidyl transferase, DT-diaphorase, and alkaline phosphatase, are discussed along with examples of their application in detecting tuberculosis, HIV, and COVID-19. Nanoparticle-based amplification approaches, including gold nanoparticles, quantum dots, and magnetic nanoparticles, are explored, highlighting their utility in detecting hepatitis B, Zika virus, and Ebola virus. Additionally, label-free amplification techniques such as electrochemical impedance spectroscopy and surface plasmon resonance are examined, with examples demonstrating their efficacy in detecting dengue virus and influenza virus. Hybrid signal amplification methods combining enzymatic, nanoparticle-based, and label-free approaches are also discussed, showcasing their potential in detecting malaria and bacterial infections. Challenges such as the need for point-of-care testing and overcoming interferences are addressed, along with future research directions, including multiplexed assays and integration with smartphones for data analysis. This review provides insights into the diverse signal amplification strategies for electrochemical biosensors and their impact on infectious disease diagnosis and control.