It is known that sulfonic groups bind to proteins' protonated amino acid side chains (NH3 + in lysine, arginine, and histidine) with additional, stabilizing hydrogen bonds formation with tyrosine . We found out that basic amino acids constitute about 10% of proteins present at the surface of studied viruses and Gram-positive bacteria (T4 major capsid protein gp23, Salmonella P22 phage major capsid protein, Escherichia phage MS2 capsid protein, Enterobacterial phage M13 capsid protein G8P, major surface proteins of S. aureus, ligand-binding A-domain of SasG protein). However, in the case of E. coli (OmpA extracellular domain), the value is significantly lower, i.e., 5.9% (Figure , Supporting Information). Therefore, there were more binding sites on the surface of virions and Gram-positive bacteria than Gram-negative bacteria. We hypothesized that this may be one of the factors determining the BB selectivity shown in the study. The fact that sulfonic compounds (with an emphasis on 2-naphthol-6-sulfonate and isatin-5-sulfonate) by default weren't selective (Figure , Supporting Information), similar to the remaining food colorants indicated the need for better understanding interactions between biomolecules and sulfonates to facilitate biotechnological applications. It should be noted that the lack of activity of CV (Figure and Figure , Supporting Information) showed that only binding to the surface was also not enough to provide protection against UV.