Paper-Based Neuraminidase Assay Sensor for Detection of Influenza Viruses

In this study, we described a paper-based neuraminidase assay sensor (PNAS) which can be applied to detect the infection by influenza viruses. The PNAS was designed and manufactured to quantitatively identify the levels of neuraminidase in the sample, which is based on colorimetric analysis using the X-Neu5Ac substrate. The limit of detection of the PNAS was determined as 0.004 U/mL of neuraminidase. According to the amount of neuraminidase in human serum, the PNAS could monitor the enzyme activity with a good linearity (R-2 > 0.99). In addition, the initial performance of the PNAS has been maintained up to 70 days in the 4 degrees C. Finally, we demonstrated whether the Michaelis-Menten kinetics is applied to the PNAS, which can show the reliability of the enzyme reactions. The kinetic studies indicated that the PNAS provides the good condition for enzyme reactions (K-m = 8.327x10(-3) M), but they were performed on paper chip nonetheless. The paper-based neuraminidase assay sensor may be useful in a wide range of rapid and safe detection of influenza virus.