Multiple aptamer recognition-based quantum dot lateral flow platform: ultrasensitive point-of-care testing of respiratory infectious diseases.

Respiratory infectious diseases spread rapidly and have a wide range of impacts, posing a serious threat to public health security. The development of a sensitive, accurate, and rapid detection method for respiratory viruses is crucial for disease prevention and control. However, existing methods are inadequate in satisfying the demand for accurate and convenient detection simultaneously. Therefore, an ultrasensitive point-of-care testing (POCT) platform based on a multiple aptamer recognition-based quantum dot lateral flow immunoassay (MARQ-LFIA) was developed in this work. This platform consisted of multiple high-affinity aptamers for recognizing different sites on a respiratory infectious virus protein, enhancing the efficiency of virus identification in complex environments. By combining a multiple aptamer recognition strategy with quantum dot fluorescent technique to construct LFIA test strips and pairing them with a high-gain portable fluorescence reader, excellent detection sensitivity and specificity were achieved in the case of coronavirus disease 2019 (COVID-19). The limits of detection were 1.427 pg mL-1 and 1643 U mL-1 towards the nucleocapsid protein and inactivated viruses, respectively, indicating that MARQ-LFIA improved detection sensitivity compared to reported methods. More critically, by testing thirty COVID-19 positive and twenty negative patient samples, the positive detection rate increased from 55.17% to 86.67% compared with commercially similar products. The universality of MARQ-LFIA was also investigated for diagnosing influenza B. We believe that MARQ-LFIA can be a promising POCT tool with potential applications in the areas of public health for the growing demand for precision diagnosis and treatment.