Reply to Zandi, M.; Soltani, S. Comment on "Alfassam et al. Development of a Colorimetric Tool for SARS-CoV-2 and Other Respiratory Viruses Detection Using Sialic Acid Fabricated Gold Nanoparticles. Pharmaceutics 2021, 13 , 502".

The comment has corrected highly debatable information, in which we claimed that the SA binds only to the hemagglutinin proteins rather than the S protein, especially for SARS-CoV-2 and MERS-CoV. The hemagglutinin is known as the main envelop glycoprotein of influenza B virus, inducing receptor binding, while neuraminidase works as a separate glycoprotein. Sialic acid (SA) is the glycoprotein that is densely projected on the surface of different mammalian cells including lung epithelial cells. Development of a Colorimetric Tool for SARS-CoV-2 and Other Respiratory Viruses Detection Using Sialic Acid Fabricated Gold Nanoparticles. [Extracted from the article]