Nanozymes featuring a mesoporous silica shell for rapid enrichment and ultrasensitive lateral flow immunoassay of influenza A

Background

Respiratory illnesses stemming from influenza A viruses represent a significant worldwide health concern. There is an immediate need for a rapid and sensitive method to detect influenza A viruses early, without requiring extra equipment.

Results

Here, we established a lateral flow immunoassay (LFIA) for the detection of influenza A (Flu A) using a "three-in-one" multifunctional mesoporous Fe₃O₄@SiO₂@Pt nanozymes (Fe₃O₄@MSiO₂@Pt NZs) with excellent magnetic separation properties, colorimetric, and peroxidase-like (POD-like) activities. Effective enrichment of target Flu A in complex samples as well as greater loading of Pt particles by mesoporous structures with large specific surface area to enhance POD-like activity can significantly improve the detection sensitivity of the LFIA. After colorimetric amplification by Fe₃O₄@MSiO₂@Pt tags catalysis, the qualitative and quantitative results of detection for Flu A nucleoprotein (Flu A-NP) were 0.01 and 0.0089 ng mL⁻¹, respectively. This indicated a sensitivity approximately 100 times greater than commercially available colloidal Au nanoparticle (AuNP)-based LFIA strips. For detection of inactivated H1N1 virus, quantification can be as low as 33 copies mL⁻¹. Moreover, it demonstrated high accuracy in pharyngeal swab sample simulation experiments.

Significance

Therefore, the proposed platform based on Fe₃O₄@MSiO₂@Pt NZs-LFIA offered a promising approach for point-of-care testing (POCT), enabling rapid and ultrasensitive diagnosis of Flu A.