Fig. 6: Investigation on interaction between SiO2@DpaZn with phosphopeptides.

a Enrichment ability of SiO2@DpaZn, SiO2@Dpa, and SiO2@NH2. b Gradient elution of nonphosphopeptides, mono-phosphopeptides (triangle), and multi-phosphopeptides (double triangles). Solid triangle indicates N-phosphopeptide (TSpHYSIMAR), and asterisk-labeled solid triangle indicates the dephosphorylated counterpart (TSHYSIMAR). c Zeta potential of SiO2@DpaZn in pH 5.0–12.0. Each value represents the mean value from n = 3 parallel experiments. The error bar is represented by SD.