Electrochemical and optical biosensors as transformative tools for multiplex detection of influenza viruses.

The influenza viruses (IVs) are major public health risk, causing immense seasonal infections, severe illness, and respiratory deaths yearly. Rapid, accessible, and precise detection is essential because the IV RNA genome facilitates genetic recombination and rapid mutation, potentially leading to new pandemic strains that evade existing diagnostic methods. Conventional gold standard technique is constrained by high costs, long turnaround times and dependence on specialized laboratory infrastructure, limiting their utility in urgent point of care (PoC) settings. To address these challenges, biosensors are emerging as a notable alternative, offering high sensitivity, speed, affordability, and portability. This paper examines the evolution of biosensing technologies for IV detection, focusing specifically on electrochemical and optical platforms. Optical biosensors, which mainly include plasmonic (SPR/LSPR), luminescent, Raman scattering, colorimetric, and interferometric systems, are valued for their exceptional sensitivity, specificity, and ability to provide real time, label free results, thereby simplifying the diagnostic workflow. Concurrently, electrochemical biosensors, including mostly amperometric, potentiometric, and impedimetric configurations, are highly suitable for PoC device miniaturization by translating biorecognition events into measurable electrical signals. Recent advancements across both modalities often utilize nanomaterials like metal nanoparticles, aptamers, and molecularly imprinted polymers to significantly enhance detection limits and selectivity, enabling the differentiation of distinct influenza strains and subtypes. Ultimately, the integration of these sensitive biosensor platforms with emerging technologies such as microfluidics and artificial intelligence is vital for creating automated, miniaturized tools that will form the foundation of next generation influenza detection and support global public health preparedness.