A Multiplexed Three-Channel Detection System for Rapid Home-Based Diagnosis of Respiratory Viruses

Acute respiratory syndrome coronavirus (SARS-CoV-2), influenza A virus (Flu A), and influenza B virus (Flu B) are highly contagious pathogens that can cause similar clinical manifestations and often co-infect, posing significant challenges for differential diagnosis and disease management. Early and accurate detection of these viruses is crucial for curbing their respiratory transmission. Therefore, there is an urgent need to develop a reliable, rapid, sensitive, and user-friendly tool for detecting multiple respiratory pathogens. Here, we present a triple-channel immunochromatographic system (TCIS) based on quantum dot fluorescent microspheres (QDFM), which includes immunochromatographic test strips and a detection platform integrated with optical and electronic modules. The TCIS utilizes a smartphone for fluorescence image extraction and filtering algorithms, enabling automatic image denoising and quantitative data analysis. Combined with high quantum yield luminescent materials, the system significantly enhances detection sensitivity. The limits of detection (LODs) for Flu B nucleoprotein, Flu A nucleoprotein, and SARS-CoV-2 N protein were as low as 0.301 ng/mL, 0.227 ng/mL, and 0.348 ng/mL, respectively. To evaluate its clinical performance, we tested saliva samples from 15 Flu A patients and 20 healthy controls, demonstrating a sensitivity of 100% and a specificity of 95.2%. This work highlights the potential of TCIS as an efficient, accessible, and accurate home-based diagnostic tool, offering a promising solution for early diagnosis.