A Printed Polarization‐Sensitive Biochip for Rapid and Accurate Detection of Respiratory Infections

Abstract Respiratory infections are the major cause of death from infectious diseases worldwide, which impose a heavy burden on public healthcare. Many respiratory viruses induce indistinguishable clinical symptoms, making accurate detection and effective surveillance challenging. Here, a polarization‐sensitive multiplex biochip is presented utilizing self‐assembled anisotropic nanochains for simultaneous colorimetric detection of multiple pathogens in human nasal, throat, and serum samples. The biochip features a patterned wettability surface, wherein the hydrophobic pattern facilitates precise sample segmentation, blocking the detection interferences. The hydrophilic areas can be utilized not only to print functionalized nanochains for selective identifications of different respiratory viruses, but also to support target preconcentration through the coffee‐ring phenomenon, enhancing the efficiency of virus detection. Furthermore, strong light confinement is shown near the nanochain surface by tailoring incident polarization, which enlarges colorimetric response sensitivity to virus loading. Thus, the simultaneous quantification of various respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), influenza A virus, influenza B virus, and adenovirus, is achieved with a detection limit of 10 PFU mL ⁻¹ . In clinical tests, influenza patients are successfully distinguished from other volunteers with an accuracy of 96.2%. This method eliminates the need for extrinsic labels or preamplification, which is expected to expand at‐home diagnostic tools for respiratory pathogens.